this case report describes the surgical technique used and clinical outcome 
 of a 15-year - old neutered female cat that had a comminuted fracture of the 
 right glenoid and scapular neck secondary to a gunshot injury that was 
 treated with glenoidectomy .
good clinical outcomes are possible with removal of the glenoid for treatment 
 of comminuted fractures of the scapulohumeral joint .
glenoidectomy is a 
 viable alternative to amputation in cats with normal neurovascular supply to 
 the affected limb .
persistent functional , pain - free lameness , muscle 
 hypertrophy and changes in shoulder range of motion are to be expected .
partial and complete scapulectomy are salvage procedures described in cats and dogs 
 with variable clinical outcomes
. the reported indications for 
 complete or partial excision of the scapula are fracture of the glenoid , chronic medial glenohumeral luxation or , more frequently , scapular neoplasia .
this report describes a 
 15-year - old neutered female domestic shorthair cat with a comminuted fracture of the 
 right glenoid and scapular neck secondary to a gunshot injury , which was treated 
 with glenoidectomy with preservation of the humeral head .
lameness in the right 
 forelimb was 3/5 , 4/5 and 1/5 preoperatively , 24 h postoperatively and 6 months 
 postoperatively , respectively .
a 15-year - old neutered female domestic shorthair cat was presented to the primary 
 care veterinarian for acute onset of right forelimb lameness .
the cat had been 
 missing for the previous 24 h and was normally an indoor / outdoor cat with free 
 access to the owner s residence . prior to this presentation , the cat was reportedly 
 healthy .
on presentation to the primary care veterinarian , the cat had a toe - touching to 
 non - weight bearing right forelimb lameness and a scab of dried blood located cranial 
 to the point of the right shoulder .
the 
 scabbed region over the cranial aspect of the point of the right shoulder was 
 clipped , and a small puncture wound approximately 5 mm in diameter was noted . 

complete blood count revealed a normocytic , normochromic , mildly regenerative 
 anaemia ( haematocrit 11.5 , reference interval [ ri ] 3045% ) .
g / l ) , decreased alkaline phosphatase enzyme 
 activity ( 13 u / l ; ri 14111
u / l ) and decreased amylase enzyme activity ( 440 u / l ; ri 
 5001500 u / l ) .
given 
 the forelimb lameness , puncture wound and marked anaemia , hypoproteinaemia and 
 fracture of the forelimb , anaemia secondary to haemorrhage was considered most 
 likely .
the cat was sedated with butorphanol ( 0.2 mg / kg ) and midazolam ( 0.2 mg / kg ) 
 intramuscularly prior to establishing intravenous ( iv ) access .
the cat was intubated 
 and general anaesthesia was maintained with isoflurane in oxygen while radiographs 
 were taken .
referral radiographs revealed a severely comminuted fracture of the scapular neck and 
 glenoid with lateral displacement ( figure 1 ) .
there were 
 fragmented metallic opacities lodged within the fractured segments of the right 
 scapula , which extended medially and dorsally in a linear trajectory .
the largest , 
 most irregular metallic fragment was observed ipsilateral and adjacent to the 
 twelfth and thirteenth thoracic ( t12 and t13 , respectively ) vertebrae . there was 
 marked increase in soft tissue opacity within the right axilla and subscapular space 
 with mild subcutaneous emphysema cranial to the right shoulder .
radiographic changes observed supported the source of the 
 lameness and anaemia to a single bullet that had penetrated the skin ventral to the 
 right mandibular ramus , tracked through the subcutaneous tissue , fractured the 
 scapular neck and glenoid , and subsequently fragmented within the axilla without 
 penetrating the thorax .
( a ) right mediolateral and ( b ) dorsoventral referral radiographic views of 
 the scapula and thorax .
note the comminuted fracture of the right distal 
 scapula , medial displacement of the humerus , axillary subcutaneous emphysema 
 with associated increase in soft tissue opacification and bullet 
 fragmentation extending from the shoulder to just lateral to the t12t13 
 intervertebral space general physical examination performed at the time of admission was similar to that 
 reported by the primary care veterinarian earlier that day .
the cat was ambulatory 
 with toe - touching to non - weight - bearing lameness in the right forelimb ( see video 1 in supple - mentary 
 material ) .
g / l , respectively , 
 which was improved compared with the results 8 h previously . given the anaemia and 
 inadequate analgesia , further in - hospital supportive care with packed red blood cell 
 transfusion if the pcv continued to decline and analgesia was planned .
iv 
 crystalloid fluids and methadone ( 0.3 mg / kg i m ; troy laboratories ) were given 
 overnight , and a transdermal fentanyl patch ( 12 g / h ; janssen - cilag ) was applied . 

the pcv / tp were monitored and remained stable , so transfusion was not performed .
the 
 cat was discharged for the weekend the next day with re - presentation scheduled for 
 the start of the following week . computed tomography ( ct ) with and without iv contrast ( 450 mg / kg iohexol 300 ; ge 
 healthcare ) under general anaesthesia
was performed 3 days after initial referral to 
 better characterise the scapular fracture , axillary vasculature and thorax .
the ct 
 revealed multiple metallic attenuating fragments and gas - attenuating pockets 
 consistent with a bullet track within the right subcutaneous tissues , muscles and 
 scapula on the right forelimb and thoracic wall ( figure 2 ) .
there was a severely comminuted 
 fracture of the right distal scapula ( figure 3 ) , with fragmentation of the glenoid 
 and adjacent increased soft tissue attenuation without iohexol extravastion , 
 suggesting fluid accumulation consistent with prior haemorrhage .
there were 
 multiple metal fragments lodged within the bone and adjacent tissues along the 
 articular processes from t11 to t13 , with the largest fragment lodged at the right 
 of the t13 spinous process and articular facet ( figure 2 ) .
there was no evidence of thrombosis or vascular compromise to 
 the axillary vessels in the right brachial plexus after iv contrast 
 administration .
light purple - coloured irregularities to the right represent bullet 
 fragments three - dimensional reconstruction of the right glenohumeral joint .
( a ) 
 lateral , ( b ) caudocranial and ( c ) medial views .
note the comminuted fracture 
 of the distal right scapula , medial displacement of the humerus and bullet 
 fragmentation .
there is fracture of the scapula 
 spine proximal to the suprahamate process owing to the degree of comminution , reconstruction of the glenoid , scapular neck and 
 the glenohumeral joint was considered unattainable .
amputation of the limb was 
 considered ; however , this was deemed to be an extreme option given the neurological 
 function of the limb was normal and the humeral head and the scapula proximal to the 
 neck were intact .
the cat was premedicated with 
 methadone ( 0.3 mg / kg i m ; troy laboratories ) .
general anaesthesia was induced with 
 diazepam ( 0.25 mg / kg ; ceva pharmaceuticals ) and ketamine ( 5 mg / kg ; troy 
 laboratories ) .
hypotension 
 ( mean arterial pressure < 60 mmhg ) determined by oscillometric non - invasive blood 
 pressure was observed during patient preparation .
two initial boluses of hartmann s 
 solution ( 10 mg / kg ) failed to improve hypotension , so fentanyl ( 310 g / kg / h ; 
 astrazeneca ) and ketamine ( 10 g / kg / min ) constant rate infusion ( cri ) were initiated 
 and maintained throughout surgery in order to reduce the end - tidal isoflurane 
 concentration to 1% . despite this ,
hypotension only resolved ( mean arterial pressue 
 > 60 mmhg ) with administration of a dopamine cri at 510 g / kg / min .
cefazolin ( 22 
 mg / kg iv ; sandoz ) was administered at induction and every 90 mins throughout 
 surgery .
the cat was positioned in left lateral recumbency and a 15 cm lateral 
 incision was made over the right scapula spine and then distal over the glenohumeral 
 joint over the proximolateral humerus .
the suprascapular and axillary nerve could 
 not be visualised , owing to extensive soft tissue damage around the scapular neck , 
 acromion and glenoid .
gelpi retractors were placed into the suprapinatus and 
 infraspinatus fossae to retract these muscles from the scapular spine and expose the 
 scapular neck .
the hamate and suprahamate processes of the acromion ( origins of the 
 deltoid muscles ) were attached to the scapular spine with a fine fibrous adhesion , 
 but had otherwise fractured as a single piece that had not displaced . the humeral 
 head was displaced medially and ventrally , and was manipulated back into a normal 
 position with bone - holding forceps .
a longitudinal fracture of the infraspinatus fossa was observed to extend from the 
 scapular neck to the level of the suprahamate process .
the supraglenoid tubercle with 
 the origin of the biceps brachii and coracobrachialis was fragmented and displaced 
 medial to the joint , so biceps and coracobrachialis tenotomy was performed and the 
 supraglenoid tubercle excised .
the joint capsule was incised close to the glenoid 
 rim , which facilitated intra - articular removal of the fragmented glenoid .
the 
 origins of the medial and lateral glenohumeral ligament were resected at the glenoid 
 to help preserve as much joint capsule as possible .
a transverse ostectomy was 
 performed with a sagittal saw across the remaining scapula approximately 1 cm 
 proximal to the suprahamate process .
the remaining joint capsule was 
 sutured over the humeral head with 2 - 0 polydiaxonone ( pds ; ethicon ) .
a 2 cm  4 cm muscle flap was created from the caudal aspect of the supraspinatus 
 muscle by incising it parallel to its fibres , and then rotating the pedicle caudally 
 between the osteotomised surface of the scapula and the joint capsule covering the 
 humeral head .
the muscle flap was sutured in place to the scapular head of the 
 deltoid , the lateral head of the triceps and the joint capsule with locking loop 
 sutures of 2 - 0 pds .
the infraspinatus fascia was apposed to the supraspinatus fascia 
 with 2 - 0 pds .
the trapezius and omotransversarius muscles were then apposed to the 
 scapular head of the deltoid with 3 - 0 pds .
there was a smooth range of motion palpable in the right shoulder , without 
 abnormal abduction , rotation or crepitus .
a 2 cm incision was then made along the 
 epaxial longissimus thoracic muscles over right side of t13 .
blunt dissection was 
 made through the muscle to retrieve a metallic fragment of bullet ; this was 
 submitted for culture and sensitivity , and was negative .
the wound region was 
 lavaged prior to closure of the muscle fascia , subcutaneous tissue and skin .
postoperative radiographs confirmed the removal of the majority of the fragmented 
 glenoid and scapula ( figure 
 4 ) .
a single sliver of bone was observed caudolateral to the humeral head 
 on postoperative radiographs ; however , this was appreciated to be extra - articular 
 and embedded in soft tissues and did not pose any obstruction to shoulder range of 
 motion .
relative dorsal 
 translation of the humeral head was appreciated compared to the contralateral 
 limb .
note 
 relative dorsal displacement of the scapula and humerus in ( b ) during 
 simulated weightbearing the cat recovered from anaesthesia with a cri of fentanyl ( 13 g / kg / h ) without 
 complication and was eating and drinking several hours after surgery . anticipating a 
 12 h onset of action , a transdermal buprenorphine patch ( 10 g / h ; mundipharma ) was 
 applied .
non - steroidal anti - inflammatories were considered but , owing to the cat s 
 anaemia and hypotension under general anaesthesia , not administered .
twelve hours 
 after surgery there was a persistent weight - bearing right forelimb lameness at a 
 walk ( see video 2 in 
 supplementary material ) ; however , the cat would hold the right forelimb off the 
 ground when not ambulating . the day after surgery
the cat was discharged with a 
 transdermal buprenorphine patch providing a week of analgesia .
a mild persistent 
 weight - bearing right forelimb lameness was appreciated at a walk ( see video 3 in supplementary 
 material ) .
the cat was able to jump up and down from a height of several steps . 

subjectively , the right forelimb looked shorter than the contralateral forelimb , and 
 the scapula was more dorsally displaced .
the range of motion was considered normal 
 and no pain or crepitus could be elicited .
the triceps , biceps and deltoid muscles 
 of the right forelimb appeared moderately hypertrophied compared with the 
 contralateral limb . at this time , the supra- and infraspinatus muscles were not 
 atrophied .
instructions were provided to the owner to continue to restrict the cat 
 to small indoor areas and to prevent it from running and jumping . at the 6 month 

recheck , there was marked atrophy of the supra- and infraspinatus muscles in 
 contrast to the 3 week recheck , suggesting that suprascapular nerve function had 
 been compromised .
the triceps , biceps and deltoid muscles remained moderately 
 hypertrophied compared with the contralateral limb .
as before , no pain could be 
 elicited with movement of the pseudoarthrosis , and range of motion was subjectively 
 comparable to the contralateral shoulder .
the cat s mechanical lameness at 6 months 
 was observed as a very slightly shortened stance phase when walking ( see video 4 in supplementary 
 material ) .
the client s impression was that the cat s right forelimb had returned to 
 normal function and the cat was capable of performing all the activities it had 
 previously carried out without overt pain ; however , it had become reluctant to jump 
 down from heights .
this report describes the surgical technique and clinical outcome of a cat that had a 
 complete glenoidectomy performed to treat a comminuted fracture secondary to a 
 gunshot injury of the distal scapula .
this case is the first known report describing 
 the successful use of a complete glenoidectomy with preservation of the humeral head 
 for management of a comminuted distal scapular fracture . several feline and 
 orthopaedic textbooks describe glenoidectomy with and without humeral head excision 
 as a salvage procedure for diseases of the shoulder joint in cats ; however , all of these sources 
 reference case reports in dogs .
there are reports in toy breed dogs of glenohumeral excisional arthroplasty being 
 performed for treatment of chronic shoulder luxation and comminuted glenoid 
 fractures . in all of these reports where glenohumeral excisional 
 arthroplasty was performed , the humeral head and the glenoid
the literature suggests that expected limb use after partial 
 scapulectomy in cats and dogs should be good to excellent when there is preservation 
 of neurological function , preservation of the glenoid and the glenohumeral joint , 
 and reconstruction of the joint s soft tissues in lightweight animals . despite these suggested 
 restrictions to ensure a favourable outcome ,
good - to - excellent clinical outcomes 
 have been reported in cats and mid - to - large breed dogs undergoing partial and total 
 scapulectomy , and in dogs undergoing 
 glenohumeral excisional arthroplasty .
these reports would support 
 that animal size should not preclude glenoidectomy or scapulectomy as limb salvage 
 procedures .
furthermore , retention of the glenoid or glenohumeral collateral 
 ligaments may not be essential to afford a good clinical outcome .
passive glenohumeral joint stability is primarily provided by the joint capsule and 
 collateral ligaments in dogs ; however , the relative 
 contribution of these to glenohumeral stability in the cat has not been 
 demonstrated .
the transarticular tendons ( specifically the supraspinatus , 
 infraspinatus , biceps brachii and subscapularis , and , less so , the coracobrachialis , 
 teres minor and teres major ) are active stabilisers of the glenohumeral joint and 
 require energy to contract and relax to maintain joint conformation .
as described 
 in this case , we were able to reconstruct or maintain some of the supporting soft 
 tissues of the glenohumeral joint , specifically the joint capsule , supraspinatus , 
 infraspinatus , teres minor and subscapularis tendons , which provided some 
 mediolateral stability to the scapulohumeral pseudarthrosis .
furthermore , the 
 moderate hypertrophy of the triceps , biceps and deltoids of the affected limb noted 
 on examination 3 weeks postoperatively suggests that stability to the pseudarthrosis 
 may be actively provided by these muscles .
examination of the cat prior to discharge 
 and again at the 3 week recheck revealed a palpable increase in proximodistal and 
 flexion / extension shoulder range of motion compared with the contralateral shoulder . 

no crepitus or pain was appreciated in the right shoulder at the 3 week recheck , and 
 limb use was considered to be good , despite a persistent mechanical lameness , which 
 is likely related to the effective shortening of the limb and alteration in the 
 shoulder range of motion .
we suspect that if part of the scapula is to be retained 
 after glenoidectomy , then closing the joint capsule , reconstructing or maintaining 
 the supraspinatus , infraspinatus and subscapularis tendons , and interposing soft 
 tissue between cut bone ends may be important to affording a good functional outcome 
 in the cat .
while the use of a muscle sling in excisional arthroplasties remains controversial , in this case it was deemed necessary owing to the expected pistoning during 
 weight bearing between the juxtaposed cut edge of the distal scapula and the humeral 
 head .
the technique described here may not be applicable to cases with concurrent 
 neurological dysfunction or fracture of the humeral head .
a good clinical outcome is possible with removal of the glenoid for treatment of 
 comminuted fractures of the scapulohumeral joint .
the surgical technique of 
 glenoidectomy is a viable alternative to amputation in cats with normal 
 neurovascular supply to the affected limb .
a persistent functional , pain - free 
 lameness , muscle hypertrophy and abnormalities in shoulder range of motion are to be 
 expected .
 case summarythis case report describes the surgical technique used and clinical outcome 
 of a 15-year - old neutered female cat that had a comminuted fracture of the 
 right glenoid and scapular neck secondary to a gunshot injury that was 
 treated with glenoidectomy.relevance and novel informationgood clinical outcomes are possible with removal of the glenoid for treatment 
 of comminuted fractures of the scapulohumeral joint . 
 glenoidectomy is a 
 viable alternative to amputation in cats with normal neurovascular supply to 
 the affected limb . 
 persistent functional , pain - free lameness , muscle 
 hypertrophy and changes in shoulder range of motion are to be expected . 
Case summary
Relevance and novel information
Introduction
Case description
Discussion
Conclusions