patellofemoral osteoarthritis ( pfoa ) commonly occurs among middle - aged and elderly people , especially among asian women .
pathogenically , lower limb alignment abnormalities will result in wear and tear on cartilage in the patellar / groove joint surface , subchondral sclerosis , and osteophytosis .
patellofemoral osteoarthritis is a common cause of anterior knee pain and severely reduces the quality of life . in our hospital , we treated 156 pfoa patients using arthroscopic knee joint debridement , patelloplasty , circumpatellar denervation , and release of the lateral patellar retinaculum .
a total of 156 pfoa patients ( 62 males , 94 females ; ages 45 - 81 years , mean 66 years ) were involved in this study .
pfoa occurred on the left side in 73 patients and on the right side in 83 patients .
the clinical manifestations included recurrent swelling and pain in the knee joint ; aggravated pain upon ascending / descending stairs , squatting down , or standing up ; positive patellar grinding tests ; pain mainly located at patellar edges ; varying degrees of quadriceps femoris atrophy ; and a sense of joint friction during activities .
knee - joint x - rays showed that the space between the patellofemoral joint was narrowed , and osteophytosis was present .
patellar axial slices showed that the patellofemoral joints degenerated , the space between patellofemoral joints was narrow , and the patella was inclined outwards .
t2-weight and three - dimensional - fat - suppressed spoiled gradient recalled echo sequence ( 3d - fs - spgr ) cartilage - sequence magnetic resonance imaging ( mri ) showed that the cartilage on the patella and femoral groove joint surface had degenerated or was lost and was mainly accompanied by slight degeneration in the menisci and tibial joints [ figure 1 ] .
three - dimensional fat - suppressed spoiled gradient recalled echo sequence cartilage sequence magnetic resonance imaging shows that the cartilage on the patella and groove surface degenerated ( red arrow ) , and this degeneration was frequently complicated by slight degeneration in the menisci and tibial joints .
the inclusion criteria were as follows : patients with pfoa , mainly from patella wear and osteophytosis only ; intact femorotibial joints , meniscus , cruciate ligaments , and collateral ligaments ; and normal lower - limb alignment and normal bending and stretching abilities .
all procedures in this group were performed by one highly - qualified orthopedic surgeon . under local anesthesia
, the surgical sites were disinfected and draped according to standard procedures , and the arthroscopy was approached from inside and outside of the knee eyes .
comprehensive detection was first conducted to assess the patellar trajectory and patellofemoral articular cartilage degeneration and to classify the cartilage defect .
next , the hyperplastic synovium , medial and lateral compartments , and lesions in the intercondylar fossa were cleared .
the lateral patellar retinaculum was released under radio frequency , and the circumpatella was denervated [ figures 2 and 3 ] . under arthroscopy ,
the surgeon observed the patellar trajectory , the bone blockage and cartilage wound margins affecting patellofemoral joint activities , and the osteophytes present around the ground patella .
axial patellar osteophytes were cleared , and the joint space increased . after awakening from anesthesia , the patients began isometric quadriceps training .
patients began straight leg raising and knee flexion and extension training and started partial weight - bearing ambulation the day after surgery .
the arthroscopic articular cartilage samples before and after surgery were classified and evaluated using lysholm and kujala scores .
lysholm knee scoring is globally used for the comprehensive evaluation of patellofemoral joint disorders and includes 8 items : limp , locking , pain , support , instability , swelling , difficulty in ascending stairs , and restriction in squatting .
kujala scoring is used for the evaluation of patellofemoral joints and covers 13 items : limp when walking , supporting weight , walking distance , symptoms occurring when ascending or descending stairs , squatting ability and symptoms , symptoms occurring when running or jumping , symptoms occurring when kneeling down for long periods , degree of knee joint pain , anterior knee swelling , accompanying abnormal patellar activity , occurrence of thigh muscle atrophy , and restriction upon knee joint bending .
the above items were tested preoperatively and again during the last follow - up to evaluate the therapeutic effects and the improvement in knee joint functions after surgery .
the quantitative data were expressed as mean  standard deviation and tested with the paired t - test , with the significance level set at  = 0.05 .
a total of 156 pfoa patients ( 62 males , 94 females ; ages 45 - 81 years , mean 66 years ) were involved in this study .
pfoa occurred on the left side in 73 patients and on the right side in 83 patients .
the clinical manifestations included recurrent swelling and pain in the knee joint ; aggravated pain upon ascending / descending stairs , squatting down , or standing up ; positive patellar grinding tests ; pain mainly located at patellar edges ; varying degrees of quadriceps femoris atrophy ; and a sense of joint friction during activities .
knee - joint x - rays showed that the space between the patellofemoral joint was narrowed , and osteophytosis was present .
patellar axial slices showed that the patellofemoral joints degenerated , the space between patellofemoral joints was narrow , and the patella was inclined outwards .
t2-weight and three - dimensional - fat - suppressed spoiled gradient recalled echo sequence ( 3d - fs - spgr ) cartilage - sequence magnetic resonance imaging ( mri ) showed that the cartilage on the patella and femoral groove joint surface had degenerated or was lost and was mainly accompanied by slight degeneration in the menisci and tibial joints [ figure 1 ] .
three - dimensional fat - suppressed spoiled gradient recalled echo sequence cartilage sequence magnetic resonance imaging shows that the cartilage on the patella and groove surface degenerated ( red arrow ) , and this degeneration was frequently complicated by slight degeneration in the menisci and tibial joints .
the inclusion criteria were as follows : patients with pfoa , mainly from patella wear and osteophytosis only ; intact femorotibial joints , meniscus , cruciate ligaments , and collateral ligaments ; and normal lower - limb alignment and normal bending and stretching abilities .
all procedures in this group were performed by one highly - qualified orthopedic surgeon . under local anesthesia ,
the surgical sites were disinfected and draped according to standard procedures , and the arthroscopy was approached from inside and outside of the knee eyes .
comprehensive detection was first conducted to assess the patellar trajectory and patellofemoral articular cartilage degeneration and to classify the cartilage defect .
next , the hyperplastic synovium , medial and lateral compartments , and lesions in the intercondylar fossa were cleared .
the lateral patellar retinaculum was released under radio frequency , and the circumpatella was denervated [ figures 2 and 3 ] . under arthroscopy ,
the surgeon observed the patellar trajectory , the bone blockage and cartilage wound margins affecting patellofemoral joint activities , and the osteophytes present around the ground patella .
axial patellar osteophytes were cleared , and the joint space increased . after awakening from anesthesia , the patients began isometric quadriceps training .
patients began straight leg raising and knee flexion and extension training and started partial weight - bearing ambulation the day after surgery .
the arthroscopic articular cartilage samples before and after surgery were classified and evaluated using lysholm and kujala scores .
lysholm knee scoring is globally used for the comprehensive evaluation of patellofemoral joint disorders and includes 8 items : limp , locking , pain , support , instability , swelling , difficulty in ascending stairs , and restriction in squatting .
kujala scoring is used for the evaluation of patellofemoral joints and covers 13 items : limp when walking , supporting weight , walking distance , symptoms occurring when ascending or descending stairs , squatting ability and symptoms , symptoms occurring when running or jumping , symptoms occurring when kneeling down for long periods , degree of knee joint pain , anterior knee swelling , accompanying abnormal patellar activity , occurrence of thigh muscle atrophy , and restriction upon knee joint bending .
the above items were tested preoperatively and again during the last follow - up to evaluate the therapeutic effects and the improvement in knee joint functions after surgery .
the quantitative data were expressed as mean  standard deviation and tested with the paired t - test , with the significance level set at  = 0.05 .
seven of the 156 patients were missed , resulting in a follow - up rate of 95.5% . during 10 - 24 ( 18.8  3.5 ) months of follow - up ,
the incisions all healed well , and no recurrence , infection or nerve vascular injury occurred .
after surgery , the average lysholm knee score improved from 73.29  4.48 to 80.93  4.21 [ table 1 ] , and the kujala score improved from 68.34  6.22 to 76.48  6.54 [ table 2 ] . paired t - tests
based on the patellofemoral articular cartilage degeneration classification , both scores were improved significantly among patients with cartilage defects i - iii , but not among patients with cartilage defect iv .
the scores for each specific item ( e.g. limp , locking , instability , pain , swelling , ascending and descending stairs , squatting ) were improved significantly ( paired t - test ) [ tables 3 and 4 ] .
preoperative and postoperative lysholm scores preoperative and postoperative kujala scores comparison of pre- and post - operative lysholm score about cartilage damage grading comparison of pre- and post - operative kujala score about cartilage damage grading
the patellofemoral joint , composed of the patella and the femur groove , is a major component of the extension apparatus of the knee . under normal gait , the patellofemoral joint bears 0.5- to 1-fold of the body weight .
however , the weight - bearing is increased to 3- to 4-fold of body weight upon walking up and down stairs and is maximized to 8-fold of body weight upon high bending .
this high stress causes wear and tear in the patellofemoral articular cartilage and thus accelerates its degeneration .
anterior knee pain is mainly caused by an abnormal patellar trajectory ( due to congenital deformity , injury or degeneration ) or patellofemoral joint malalignment .
patellar subluxation alters the contact surface of the patellofemoral joint and increases the pressure on the joint surface , which leads to abnormal stress imposed on the patella , structural destruction of the cartilage collagen fibers , and finally , cartilage wear , tear and degeneration .
because the patellae are rich in nerve endings , exposure of the nerve endings below the cartilage will also induce anterior knee pain .
the tension on the lateral patellar retinaculum will lead to pressure on the lateral surface of the patellofemoral joint and finally to degeneration of the articular cartilage . according to lin et al .
study , the incidence rate of pfoa among people older than 50 years is 6.3% and is higher among females .
the wear and tear on the patellofemoral joint is intensified by long - term rapid and forced bending and stretching in the knee joint , which are major causes of pfoa .
non - surgical treatments include limitation of movement , pharmacologic symptom relief , and injection of hyaluronic acid into the articular cavity . as the condition progresses , however , the above treatments are unable to adequately relieve pain and/or symptoms .
traditional surgical therapies include advancement of the tibial tuberosity , patellofemoralarthroplasty , and total knee replacement
. however , invasiveness , frequent bleeding and surgical risks limit the application of these approaches . moreover , arthroplasty is unsuitable for young patients .
local blocking of the patellofemoral joint was tested among patients whose femorotibial joint , meniscus , cruciate ligaments and collateral ligaments were all intact .
these patients then underwent release of the lateral patellar retinaculum to relieve the high external patellofemoral pressure for circumpatellar denervation .
the results proved that the pain - killing effects were significant with few complications , despite the presence of varying degrees of cartilage defects .
circumpatellar nerves include the cutaneous nerves , the superior branch of the saphenous nerve , and the joint branch of the knee extensor muscle [ figure 4 ] .
the superior branch of the saphenous nerve ( also called the patellar branch ) passes through the internal superior border of the patella into the subcutaneous prepatellar area and is located in the prepatellar skin .
the joint branch of the knee extensor muscle includes the interior , medial and lateral femoral muscular branches ; the knee joint muscular branch ; and the anterior branch of the obturator nerve .
the interior femoral muscular branch originates from the obturator nerve or saphenous nerve and is divided into two branches after entering the joint capsule .
, each nerve passes through the joint capsule , is distributed in the articular synovial area , and forms the somatic nerve and autonomic nerve network in the joint . in one study ,
no significant difference between the experimental and control group was observed ( via microscopy ) in articular cartilage thickness after the denervation of rabbit knees .
moreover , there was no effect on the articular cartilage tissue structure of the knee joint nerve branch , and the knee joint partial denervation therapy was determined to be feasible .
therefore , in tka and arthroscopic debridement , through synovectomy , articular branch of the patella peripheral denervation , to reduce the patellofemoral joint pain has reasonable mechanism of anatomy .
the treatment of patellofemoral arthritis includes many surgical procedures , such as arthroscopic debridement , drilling or microfracture surgery , lateral retinaculum release , tibial tuberosity advancement , patella thin cut surgery , patellar resection , patellofemoralarthroplasty , and tka , many of which can be combined .
arthroscopy and drilling or microfracture surgery may have an effect on mild to moderate cartilage damage , but the long - term efficacy remains unclear .
simple lateral retinaculum release is only appropriate for patella displacement or tilt ; in previous studies , the force line changes were effective , but the results were controversial .
the extensor force line was relatively normal in appropriate transposition within the anterior tibial tuberosity .
there are reports that there is a significant pain relief effect of patella thin cut surgery for pure pfoa .
however , this approach is not recommended for severe abrasions or when the patella thickness is < 20 mm .
patellar resection may lead to quadriceps weakness , reducing the range of motion and leaving the femoral condyle vulnerable to trauma and without enough protection .
total knee arthroplasty is a good choice for older patients , cases of severe functional limitations or bilateral knee involvement and for patients who perform mild physical labor .
however , in relatively young patients or in very physically active pfoa patients , tka is not the best choice .
the group of patients who received outpatient treatment to limit their activity and who received oral nsaids , glucosamine and intra - articular injections of sodium hyaluronate for more than 3 months experienced less - than - ideal relief .
the 3d - fs - spgr sequence is recognized as one of the best academic cartilage mri sequences .
this technique can show transparent cartilage clearly and can accurately locate not only large cartilage defects but also small superficial cartilage wear .
spgr increases the contrast of articular cartilage and subchondral bone to improve the signal to noise ratio of the cartilage image , allowing the cartilage to be displayed more clearly .
normal articular cartilage in the 3d - fs - spgr sequence demonstrates a significantly high signal , and in the most areas of joint cartilage , delamination can be observed .
thin line , volume scanning and 3d reconstruction , and quantitative measurement of the thickness and volume of cartilage can also be performed to identify small lesions in the joint .
the 3d - fs - spgr sequence has high sensitivity and specificity for knee articular cartilage degeneration that is consistent with arthroscopy .
based on these findings , we can roughly judge the degeneration of articular cartilage by preoperative mri .
after arthroscopic surgery in mild to moderate osteoarthritis and i - iii grade cartilage degeneration , knee pain relief was clear and the majority of joint function improved significantly .
the aims of treatment of pfoa are to recover the inosculation of the patellofemoral joint , balance the soft tissues , and eliminate the primary causes for patellofemoral joint pain .
patelloplasty is able to lower the patellar lateral pressure , correct the patellar motion trajectory , improve bad contact on patellofemoral joint surfaces , prevent wear and tear on the patellofemoral joint , and delay degeneration .
radiofrequency burning with denervation is able to clear away a portion of the circumpatellar nerves , reduce the nerve conduction of pain , and relieve anterior knee pain . with the above treatments , we eliminated the biomechanical factors affecting knee joint activities and blocked the vicious circle of degeneration and injury . moreover , the articular cavity was washed with enough saline water to fully eliminate the worn areas and inflammatory factors and to alleviate inflammatory reactions , which were the objectives of treatment .
this technique uses conventional arthroscopic electrical cauterization of peripatellar synovial tissue , partial removal of the peripheral nerve with patella osteophyte drill grinding , and grinding of the hyperplasia .
this operation can remove diseased tissue while maximizing preservation of normal cartilage and synovial hyperplasia , clean up around the patella , and improve patellofemoral involution relations . the operation reduces inflammatory substances caused by the friction of the patellofemoral joint hyperplasia , thereby reducing the pain . the patella is composed of different bundle branches , but peripheral nerve distributions overlap .
therefore , even if some denervation exists , it will not completely block the patellar plexus nerve , preventing sensory loss in the patellar skin .
this procedure of cutting the patellar plexus nerve around the patellar cartilage does not damage the patella in front of the tissue .
the main patellar vascular holes are on the front  area of the patella and hence it will not result in patellar fracture , necrosis or other complications .
, through large randomized controlled studies , found that there was no difference between arthroscopic surgery and control subjects after treatment for osteoarthritis of the knee .
thus , they concluded that arthroscopic surgery is just a placebo treatment for the disease .
while this conclusion about arthroscopic techniques has a certain reference value , it was published more than 10 years ago , so it does not represent the current state of emerging technologies and new perspectives .
the technique described here flushes the inflammatory factors to relieve inflammation , removes the source of patellofemoral malalignment osteophytes , and denervates nerve endings ; although it can not reverse the process of osteoarthritis , this approach was able to relieve pain and delay joint replacement surgery .
however , this procedure was not very effective for patients with a low degree of cartilage defect and thus should not be their first treatment choice .
the follow - up results show that among patients with degree i - iii cartilage degeneration , both lysholm and kujala scores improved significantly . in conclusion , the therapeutic effects for the treatment of pfoa with arthroscopic patelloplasty and circumpatellar denervation are closely associated with the degree of patellofemoral articular cartilage degeneration .
this procedure is a minimally invasive procedure that lies between conservative treatment and joint replacement surgery .
moreover , this approach is accepted by patients who do not obtain satisfactory results after conservative treatment and can not afford the financial cost of joint replacement .
this technique , as a therapeutic method , is suitable for mild - to - moderate patellofemoral arthritis , relieves pain to a certain extent , improves quality of life , delays joint replacement , and delays the progression of pfoa .
however , the main limitation of this procedure is that it is difficult to obtain a better curative effect for patients with more severe articular cartilage degeneration and poor knee function .
the long - term effects of this procedure will require further clinical observation and research .
the patellofemoral joint , composed of the patella and the femur groove , is a major component of the extension apparatus of the knee . under normal gait , the patellofemoral joint bears 0.5- to 1-fold of the body weight .
however , the weight - bearing is increased to 3- to 4-fold of body weight upon walking up and down stairs and is maximized to 8-fold of body weight upon high bending .
this high stress causes wear and tear in the patellofemoral articular cartilage and thus accelerates its degeneration .
anterior knee pain is mainly caused by an abnormal patellar trajectory ( due to congenital deformity , injury or degeneration ) or patellofemoral joint malalignment .
patellar subluxation alters the contact surface of the patellofemoral joint and increases the pressure on the joint surface , which leads to abnormal stress imposed on the patella , structural destruction of the cartilage collagen fibers , and finally , cartilage wear , tear and degeneration .
because the patellae are rich in nerve endings , exposure of the nerve endings below the cartilage will also induce anterior knee pain .
the tension on the lateral patellar retinaculum will lead to pressure on the lateral surface of the patellofemoral joint and finally to degeneration of the articular cartilage . according to lin et al .
study , the incidence rate of pfoa among people older than 50 years is 6.3% and is higher among females .
the wear and tear on the patellofemoral joint is intensified by long - term rapid and forced bending and stretching in the knee joint , which are major causes of pfoa .
non - surgical treatments include limitation of movement , pharmacologic symptom relief , and injection of hyaluronic acid into the articular cavity . as the condition progresses , however , the above treatments are unable to adequately relieve pain and/or symptoms .
traditional surgical therapies include advancement of the tibial tuberosity , patellofemoralarthroplasty , and total knee replacement
. however , invasiveness , frequent bleeding and surgical risks limit the application of these approaches . moreover , arthroplasty is unsuitable for young patients .
local blocking of the patellofemoral joint was tested among patients whose femorotibial joint , meniscus , cruciate ligaments and collateral ligaments were all intact .
these patients then underwent release of the lateral patellar retinaculum to relieve the high external patellofemoral pressure for circumpatellar denervation .
the results proved that the pain - killing effects were significant with few complications , despite the presence of varying degrees of cartilage defects .
circumpatellar nerves include the cutaneous nerves , the superior branch of the saphenous nerve , and the joint branch of the knee extensor muscle [ figure 4 ] .
the superior branch of the saphenous nerve ( also called the patellar branch ) passes through the internal superior border of the patella into the subcutaneous prepatellar area and is located in the prepatellar skin .
the joint branch of the knee extensor muscle includes the interior , medial and lateral femoral muscular branches ; the knee joint muscular branch ; and the anterior branch of the obturator nerve .
the interior femoral muscular branch originates from the obturator nerve or saphenous nerve and is divided into two branches after entering the joint capsule .
, each nerve passes through the joint capsule , is distributed in the articular synovial area , and forms the somatic nerve and autonomic nerve network in the joint . in one study ,
no significant difference between the experimental and control group was observed ( via microscopy ) in articular cartilage thickness after the denervation of rabbit knees .
moreover , there was no effect on the articular cartilage tissue structure of the knee joint nerve branch , and the knee joint partial denervation therapy was determined to be feasible .
therefore , in tka and arthroscopic debridement , through synovectomy , articular branch of the patella peripheral denervation , to reduce the patellofemoral joint pain has reasonable mechanism of anatomy .
the treatment of patellofemoral arthritis includes many surgical procedures , such as arthroscopic debridement , drilling or microfracture surgery , lateral retinaculum release , tibial tuberosity advancement , patella thin cut surgery , patellar resection , patellofemoralarthroplasty , and tka , many of which can be combined .
arthroscopy and drilling or microfracture surgery may have an effect on mild to moderate cartilage damage , but the long - term efficacy remains unclear .
simple lateral retinaculum release is only appropriate for patella displacement or tilt ; in previous studies , the force line changes were effective , but the results were controversial .
the extensor force line was relatively normal in appropriate transposition within the anterior tibial tuberosity .
there are reports that there is a significant pain relief effect of patella thin cut surgery for pure pfoa .
however , this approach is not recommended for severe abrasions or when the patella thickness is < 20 mm .
patellar resection may lead to quadriceps weakness , reducing the range of motion and leaving the femoral condyle vulnerable to trauma and without enough protection .
total knee arthroplasty is a good choice for older patients , cases of severe functional limitations or bilateral knee involvement and for patients who perform mild physical labor .
however , in relatively young patients or in very physically active pfoa patients , tka is not the best choice .
the group of patients who received outpatient treatment to limit their activity and who received oral nsaids , glucosamine and intra - articular injections of sodium hyaluronate for more than 3 months experienced less - than - ideal relief .
the 3d - fs - spgr sequence is recognized as one of the best academic cartilage mri sequences .
this technique can show transparent cartilage clearly and can accurately locate not only large cartilage defects but also small superficial cartilage wear .
spgr increases the contrast of articular cartilage and subchondral bone to improve the signal to noise ratio of the cartilage image , allowing the cartilage to be displayed more clearly .
normal articular cartilage in the 3d - fs - spgr sequence demonstrates a significantly high signal , and in the most areas of joint cartilage , delamination can be observed .
thin line , volume scanning and 3d reconstruction , and quantitative measurement of the thickness and volume of cartilage can also be performed to identify small lesions in the joint .
the 3d - fs - spgr sequence has high sensitivity and specificity for knee articular cartilage degeneration that is consistent with arthroscopy .
based on these findings , we can roughly judge the degeneration of articular cartilage by preoperative mri .
after arthroscopic surgery in mild to moderate osteoarthritis and i - iii grade cartilage degeneration , knee pain relief was clear and the majority of joint function improved significantly .
the aims of treatment of pfoa are to recover the inosculation of the patellofemoral joint , balance the soft tissues , and eliminate the primary causes for patellofemoral joint pain .
patelloplasty is able to lower the patellar lateral pressure , correct the patellar motion trajectory , improve bad contact on patellofemoral joint surfaces , prevent wear and tear on the patellofemoral joint , and delay degeneration .
radiofrequency burning with denervation is able to clear away a portion of the circumpatellar nerves , reduce the nerve conduction of pain , and relieve anterior knee pain . with the above treatments , we eliminated the biomechanical factors affecting knee joint activities and blocked the vicious circle of degeneration and injury .
moreover , the articular cavity was washed with enough saline water to fully eliminate the worn areas and inflammatory factors and to alleviate inflammatory reactions , which were the objectives of treatment .
this technique uses conventional arthroscopic electrical cauterization of peripatellar synovial tissue , partial removal of the peripheral nerve with patella osteophyte drill grinding , and grinding of the hyperplasia .
this operation can remove diseased tissue while maximizing preservation of normal cartilage and synovial hyperplasia , clean up around the patella , and improve patellofemoral involution relations .
the operation reduces inflammatory substances caused by the friction of the patellofemoral joint hyperplasia , thereby reducing the pain .
therefore , even if some denervation exists , it will not completely block the patellar plexus nerve , preventing sensory loss in the patellar skin .
this procedure of cutting the patellar plexus nerve around the patellar cartilage does not damage the patella in front of the tissue .
the main patellar vascular holes are on the front  area of the patella and hence it will not result in patellar fracture , necrosis or other complications .
, through large randomized controlled studies , found that there was no difference between arthroscopic surgery and control subjects after treatment for osteoarthritis of the knee .
thus , they concluded that arthroscopic surgery is just a placebo treatment for the disease . while this conclusion about arthroscopic techniques has a certain reference value , it was published more than 10 years ago , so it does not represent the current state of emerging technologies and new perspectives .
the technique described here flushes the inflammatory factors to relieve inflammation , removes the source of patellofemoral malalignment osteophytes , and denervates nerve endings ; although it can not reverse the process of osteoarthritis , this approach was able to relieve pain and delay joint replacement surgery .
however , this procedure was not very effective for patients with a low degree of cartilage defect and thus should not be their first treatment choice .
the follow - up results show that among patients with degree i - iii cartilage degeneration , both lysholm and kujala scores improved significantly . in conclusion , the therapeutic effects for the treatment of pfoa with arthroscopic patelloplasty and circumpatellar denervation are closely associated with the degree of patellofemoral articular cartilage degeneration .
this procedure is a minimally invasive procedure that lies between conservative treatment and joint replacement surgery .
moreover , this approach is accepted by patients who do not obtain satisfactory results after conservative treatment and can not afford the financial cost of joint replacement .
this technique , as a therapeutic method , is suitable for mild - to - moderate patellofemoral arthritis , relieves pain to a certain extent , improves quality of life , delays joint replacement , and delays the progression of pfoa .
however , the main limitation of this procedure is that it is difficult to obtain a better curative effect for patients with more severe articular cartilage degeneration and poor knee function .
the long - term effects of this procedure will require further clinical observation and research .
 background : patellofemoral osteoarthritis commonly occurs in older people , often resulting in anterior knee pain and severely reduced quality of life . 
 the aim was to examine the effectiveness of arthroscopic patelloplasty and circumpatellar denervation for the treatment of patellofemoral osteoarthritis ( pfoa).methods : a total of 156 pfoa patients ( 62 males , 94 females ; ages 45 - 81 years , mean 66 years ) treated in our department between september 2012 and march 2013 were involved in this study . 
 clinical manifestations included recurrent swelling and pain in the knee joint and aggravated pain upon ascending / descending stairs , squatting down , or standing up . 
 pfoa was treated with arthroscopic patelloplasty and circumpatellar denervation . 
 the therapeutic effects before and after surgery were statistically evaluated using lysholm and kujala scores . 
 the therapeutic effects were graded by classification of the degree of cartilage defect.results:a total of 149 cases were successfully followed up for 14.8 months , on average . 
 the incisions healed well , and no complications occurred . 
 after surgery , the average lysholm score improved from 73.29 to 80.93 , and the average kujala score improved from 68.34 to 76.48 . 
 this procedure was highly effective for patients with cartilage defects i - iii but not for patients with cartilage defect iv.conclusions:for pfoa patients , this procedure is effective for significantly relieving anterior knee pain , improving knee joint function and quality of life , and deferring arthritic progression . 
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M
Basic information
Surgical procedures
Observation items and therapeutic evaluation
Statistical methods
R
D
Anatomical analysis of patellofemoral joint
Distribution of circumpatellar nerves
Significance