parkinson 's disease ( pd ) is a progressive neurodegenerative disorder associated with various motor and non - motor features that adversely affect function to varying degrees depending on the patient7 ) .
pd typically affects patients in the seventh decade , and the cardinal signs of pd include resting tremor , rigidity , bradykinesia , and postural instability .
in addition , a stooped posture and masked facies are other significant findings in patients with pd .
several spinal deformities including camptocormia or bent spine syndrome , anterocollis , scoliosis , myopathy - induced postural deformity , and pisa syndrome are also associated with pd12 ) .
the frequency of kyphoscoliosis in patients with pd is approximately 7% , which is much higher than that of scoliosis in an age - matched population without pd12 ) .
the therapeutic options for pd range from medical treatment to neurosurgical treatment , including deep brain stimulation of the subthalamic nucleus and intramuscular botox injections .
surgical correction of these deformities should be considered for patients who have reached a severe stage in order to correct the deformity and restore mobility and functions3 ) .
spinal surgery in patients with pd is very challenging , and is associated with a high rate of postoperative complication and surgical revisions due to instrument failure . here
, we report a case of pd with a fixed spinal deformity that was treated with a relatively short segment fixation and corrective fusion surgery .
a 70-year - old female patient presented with complaints of stooping associated with severe back pain radiating to the left lower limb for a period of 3.5 years .
the patient was unable to lie on her back comfortably and reported severe depression due to her condition .
she had previously received a diagnosis of pd , for which she had taken regular oral medications for the past 10 years .
the patient had a history of multiple spinal surgeries ( total of 4 ) due to instrument - related failures for neurogenic intermittent claudication and stooping ; however , none of the surgical interventions had improved her pain or stooping posture .
the patient had significant kyphoscoliosis on examination , but the straight leg raise test , patrick 's sign , and sciatic nerve compression tests were all negative .
detailed motor and sensory examinations were conducted , which showed that her left ankle dorsiflexion was weaker than that of the right ( grade 3/5 and 4/5 respectively ) ; similar results were seen for big toe dorsiflexion ( grade 3/5 and 4/5 respectively ) .
the patient had hypoesthesia in the lt l5 dermatome , and deep tendon reflexes were bilaterally hypoactive .
1 ) showed generalized osteoporotic changes with pulling out of the l5 screws and rods and marked sagittal imbalance .
x - ray also revealed compensatoryreactive thoracic straightening and cervical hyperextension , which was apparent from the patient 's photograph .
pelvic and spinal sagittal parameters were calculated , which clearly revealed the degree of sagittal imbalance present in the patient .
considering the patient 's degree of deformity and pain , we elected to perform revision surgery .
pedicle screws and rods were reinserted from the l1to s1 levels with iliac screws after performing a partial pedicle subtraction osteotomy ( ppso ) at the l4 level with removal of the intervertebral discs at the level of l34 ( fig .
the patient 's intraoperative and postoperative periods were uneventful , and she was able to walk with a straight back without any support a few days postoperatively .
pre and postoperative surgical outcomes were measured with modified scoliosis research society-23 outcome instrument scoring system ( table 1 ) .
a 70-year - old female patient presented with complaints of stooping associated with severe back pain radiating to the left lower limb for a period of 3.5 years .
the patient was unable to lie on her back comfortably and reported severe depression due to her condition .
she had previously received a diagnosis of pd , for which she had taken regular oral medications for the past 10 years .
the patient had a history of multiple spinal surgeries ( total of 4 ) due to instrument - related failures for neurogenic intermittent claudication and stooping ; however , none of the surgical interventions had improved her pain or stooping posture .
the patient had significant kyphoscoliosis on examination , but the straight leg raise test , patrick 's sign , and sciatic nerve compression tests were all negative .
detailed motor and sensory examinations were conducted , which showed that her left ankle dorsiflexion was weaker than that of the right ( grade 3/5 and 4/5 respectively ) ; similar results were seen for big toe dorsiflexion ( grade 3/5 and 4/5 respectively ) .
the patient had hypoesthesia in the lt l5 dermatome , and deep tendon reflexes were bilaterally hypoactive .
1 ) showed generalized osteoporotic changes with pulling out of the l5 screws and rods and marked sagittal imbalance .
x - ray also revealed compensatoryreactive thoracic straightening and cervical hyperextension , which was apparent from the patient 's photograph .
pelvic and spinal sagittal parameters were calculated , which clearly revealed the degree of sagittal imbalance present in the patient .
considering the patient 's degree of deformity and pain , we elected to perform revision surgery .
pedicle screws and rods were reinserted from the l1to s1 levels with iliac screws after performing a partial pedicle subtraction osteotomy ( ppso ) at the l4 level with removal of the intervertebral discs at the level of l34 ( fig .
the patient 's intraoperative and postoperative periods were uneventful , and she was able to walk with a straight back without any support a few days postoperatively .
pre and postoperative surgical outcomes were measured with modified scoliosis research society-23 outcome instrument scoring system ( table 1 ) .
surgical management of fixed spinal deformities in patients with pd is challenging . indeed , due to disease progression itself and ongoing osteoporosis , both the treating surgeon and patient need to be aware of the increased risk of recurrent kyphosis and instrument failure , which can necessitate multiple revision surgeries .
the literature on this topic is relatively sparse , and there is no established consensus regarding standard management of fixed spinal deformities in patients with pd .
however , upadhyaya et al.15 ) suggested a treatment algorithm for patients with pd and spinal deformities , in which they advocated performing deep brain stimulation surgery ( dbs ) first for pd patients followed by a short - segment spinal decompression for myelopathy or radiculopathy .
however , they indicated that if patients do not meet the standard criteria for dbs surgery , then a short - segment spinal decompression and fusion alone can be performed .
they further emphasized the importance of performing long - segment spinal deformity correction and decompression only in those patients with minimal co - morbidities and with high motivation .
unfortunately , long - segment spinal fixation in camptocormic patients is associated with a complication rate of nearly 100%15 ) . in the present case ,
the patient initially underwent an anterior lumbar inter body fusion ( alif ) of the l3 to s1 level followed by posterior decompression and pedicle screw fixation ( psf ) .
unfortunately , the screws and cage pulled out and she underwent an anterior augmented pedicle screw and cage insertion surgery . following augmentation surgery she complained of leg pain due to l4 root irritation .
since all of these procedures were performed outside of our center , no proper surgical records or clinical radiographs could be obtained during the patient 's first visit to our center .
the lumbosacral x - rays taken at our center clearly showed the presence of instrument failure with loosening of the s1 screws and displaced rods , which led to our diagnosis of iatrogenic flat back syndrome .
the previous alif and psf surgeries in our patient had been performed well , and the initial presentation of the patient was attributed to spinal stenosis .
the patient had obvious osteoporosis and was in a progressive state of pd , and thus there was no proper fusion of the inter body cage which led to loosening of the screws . as a result
, the patient had previously undergone bone cement augmentation cage placement with screw fixation in order to resolve instrument failure .
many studies have been performed for the use of bone cement as an augmentation technique during spinal fusion surgeries of osteoporotic bones561017 ) . however , augmentation alone is not sufficient for preventing construct failures . in the patient described in this report ,
we could have corrected both construct failure and sagittal imbalance via a transperitoneal approach ; however , this involves manipulation of several vascular structures and other anatomical structures around the retroperitoneum . as our patient had a history of multiple anterior surgeries , the likelihood of intraoperative and postoperative complications
specifically , the patient had stooping as a result of compensatory thoracic straightening with further cervical hyperextension to maintain the vertical gaze , and through interviews and physical examinations we were able to associate her symptoms to spinal stenosis . based on this diagnosis , we performed a grade iv osteotomy13 ) at the l4 level ( ppso with l34 disc removal ) .
bilateral iliac screws were inserted along with the pedicle screws from l1 to s1 for improved and maximum stability of her spine .
spinal surgery in patients with pd is prone to complications for a number of reasons9 ) .
the factors contributing to these complications include old age and prevalence of severe osteoporosis , which markedly decreases the fusion rate .
surgical outcomes are further worsened by the pulling out of screws and deteriorating motor function .
on the other hand , radiological evidence of good fusion rates among patients treated surgically led moon et al.9 ) to conclude that short - segment fusion confined to the lumbar region generally achieves good results . in our institution
we categorize such patients under one of the two categories including sagittal imbalance disease and sagittal imbalance syndrome . and in this particular case , although the patient had degenerative flat back , we categorized the patient under the sagittal imbalance syndrome group as she had complaints of mild discomfort related to self - image , pain and functions . in such cases
we often perform relatively short level fusion especially in lumbar vertebras even if lumbar lordosis ( ll ) would not have been restored in accordance with pelvic incidence ( pi ) .
had the patient complained of moderate to severe discomfort , we would have categorized under the sagittal imbalance disease category and a relatively long level ( thoracic included ) fusion with resultant ll exceeding the pi value would have been considered . in our case ,
the patient 's major complaints were related to claudication without any complaints related to camptocormia hence we considered relatively short level fusion surgery is justifiable . in a case
series of 14 patients , babat et al.2 ) reported the increased risk of postoperative instrument failures and revision surgeries , and went on to propose a mechanism of ongoing kyphosis adjacent to the levels operated in pd patients .
they suggested the primary causes of the revisions to be adjacent segment disease , material failure or pullout , pseudoarthrosis , and infection .
likewise , a case study of 12 patients with pd undergoing corrective spinal surgeries was published by bourghli et al.3 ) , who reported increased incidence of instrument failure and need for revision surgeries in such patients .
another explanation for surgicalcomplications in pd patients might be the coexistence of osteoporosis and vitamin d deficiency resulting in overall reduction of bone mineral density9 ) .
in addition to progressive degeneration , improper reconstruction of the spino - pelvic balance with a special focus on ll8 ) resulted in progressive kyphosis in our patient , which eventually led to screw failures and revision surgeries .
indeed , radiographic examinations clearly revealed the presence of severe osteoporosis and degenerative changes ; however , after performing osteotomy with pedicle screw insertion from l1 to s1 along with iliac screws insertion , the sagittal balance was maintained , resulting in correction of the deformity .
both bridwell et al.4 ) and wadia et al.16 ) advocated for the use of pso to gain further sagittal plane correction up to 30 to 40. in a case report of camptocormia in pd , peek et al.11 ) emphasized the establishment of substantial forces on the caudal end for stability along with multiple fixation points and anterior column support while performing revision surgeries . with the advent of cutting - edge medical procedures leading to a longer average life span , age - related debilitating diseases are becoming more common .
pd is one such example , and causes not only physical debilitation , but emotional and economic effects as well .
it is estimated that camptocormia is present in 7% of patients with pd14 ) , which indicates the high probability of corrective spinal surgeries and need for multiple revisions in these patients .
although spinal surgeries , especially revision surgeries in patients with pd are regarded as complicated and unfavorable outcomes are common , we were able to achieve a good result in one such patient .
spinal deformitiesare very common in patients with pd , but deformity - correcting surgeries in such patients should be performed cautiously due to the increased incidence of intraoperative and postoperative complications including instrument failure .
thus , we concluded that revision surgery in patients with pd can be undertaken only after proper planning , and should involve restoration of sagittal balance and stabilization .
importantly , even a short segment fixation and corrective fusion surgery can be beneficial in such patients .
nevertheless , the most important aspect of surgical treatment in patients with pd is the realization that unfavorable surgical outcomes are inevitable due to the natural course of the disease itself9 ) .
 parkinson 's disease ( pd ) patients frequently have several spinal deformities leading to postural instabilities including camptocormia , myopathy - induced postural deformity , pisa syndrome , and progressive degeneration , all of which adversely affect daily life activities . to improve these postural deformities and relieve the related neurologic symptoms , patients often undergo spinal instrumentation surgery . due to progressive degenerative changes related to pd itself and other complicating factors , 
 patients and surgeons are faced with instrument failure - related complications , which can ultimately result in multiple revision surgeries yielding various postoperative complications and morbidities . here , we report a representative case of a 70-year - old pd patient with flat back syndrome who had undergone several revision surgeries , including anterior and posterior decompression and fusion for a lumbosacral spinal deformity . the patient ultimately benefitted from a relatively short segment fixation and corrective fusion surgery . 
INTRODUCTION
CASE REPORT
History and examination
Operative procedure & postoperative course
DISCUSSION
CONCLUSION