Glenoid vault perforation in total shoulder arthroplasty: Do we need computer guidance?

The proliferation of computer 3D simulation and computer-generated guides is aimed at minimizing perforation of the glenoid vault by glenoid pegs in shoulder arthroplasty, based on assumptions that perforation leads to worse outcomes by component loosening and potential failure. We evaluated outcomes of glenoid peg perforation testing the assumption that perforation produces worse results. Eighty-three shoulders underwent shoulder arthroplasty with pegged hybrid fixation (bone-ingrowth flanged central glenoid peg and peripheral cemented pegs) without precision signal injector guides or use of 3D planning software. Outcomes were determined by American Shoulder and Elbow Score and Oxford Shoulder Score. Fine slice CT determined the presence of vault perforation and the extent of lucent lines at the prosthesis-bone interface and bony morphology of the vault perforation. Follow-up was 46.7 months (24-99). Seven shoulders (8%) demonstrated perforation of glenoid vault. Bony ingrowth and cortical overgrowth occurred despite perforation, with no clinically significant differences in clinical or radiological outcomes in shoulders with and without glenoid vault perforation. None of these patients underwent revision surgery. Despite not utilizing computer planning and/or guides, 92% of implants did not perforate the glenoid vault. However, glenoid vault perforation in our series produced excellent outcomes with no increased risk of revision as a result of glenoid vault perforation.

Do magnetic resonance imaging abnormalities of the non-dominant wrist correlate with ulnar-sided wrist pain in elite tennis players?

OBJECTIVE: Ulnar-sided injuries of the non-dominant wrist are common in elite tennis players that use the double-handed backhand technique. This study aimed to define the relationship between ulnar-sided wrist pain in symptomatic and asymptomatic elite tennis players, and the presence of abnormalities on magnetic resonance imaging (MRI). MATERIALS AND METHODS: Fourteen symptomatic tennis players, 14 asymptomatic tennis players, and 12 healthy controls who did not play tennis, were analyzed prospectively, after undergoing MRI of their non-dominant wrist. Five anatomical regions were analyzed, thought to relate to ulnar-sided wrist pain. These consisted of the triangular fibrocartilage complex (TFCC), ulnar collateral ligament (UCL), extensor carpi ulnaris tendon (ECU), osseous-articular structures, and ganglia. Images were independently reviewed by two blinded musculoskeletal radiologists. RESULTS: Non-dominant, ulnar-sided, wrist pain in elite tennis players was not statistically significantly associated with an increased number of MRI abnormalities when compared with asymptomatic tennis players (p > 0.05). However, some evidence of statistical association was seen with an increased prevalence of ECU tendon abnormalities (OR = 8.0, 95% CI = (0.74, 20.00), p = 0.07). A statistically significant increase in MRI abnormalities of osseous structures (OR = 15.1, 95% CI = (1.56, 656.05), p = 0.02) and the dorsal radioulnar ligament (DRUL) (OR = 12.5, 95% CI = (2.15, 111.11), p = 0.03), was observed in symptomatic players compared with controls. CONCLUSIONS: Non-dominant, ulnar-sided, wrist pain in a subgroup of elite tennis players using a double-handed backhand technique is not associated with a statistically significant increased prevalence of MRI abnormalities when compared with asymptomatic tennis players, other than some evidence of statistical association with ECU tendon abnormalities. Therefore, significance of MRI abnormalities should be interpreted in the context of clinical findings.

Current trends in the evaluation and treatment of SLAP lesions: analysis of a survey of specialist shoulder surgeons.

BACKGROUND: Controversies exist in the classification and management of superior labral anterior and posterior (SLAP) lesions. Our aims were to assess the concordance rate of a group of specialist shoulder surgeons on the diagnosis of SLAP types and to assess the current trends in treatment preferences for different SLAP types. METHODS: Shoulder surgeons (N = 103) who are members of the Shoulder and Elbow Society of Australia were invited to participate in a multimedia survey on the classification and management of SLAP lesions. Response rate was 36%. The survey included 10 cases, each containing a short clinical vignette followed by an arthroscopic video depicting varying types of SLAP lesions. Surgeons were asked to classify the lesions and to recommend treatment. RESULTS: There is low interobserver agreement in classifying SLAP lesions. The most common misdiagnosis of type I lesion was as a type II, and vice versa. Surgeons preferred to treat type II SLAP lesions in younger patients (<35 years) with labral repair and in older patients with biceps tenodesis. The most commonly preferred repair technique for type II lesion was with suture anchors placed both anterior and posterior to the biceps tendon. For all lesion types, biceps tenotomy was a far less commonly preferred procedure than biceps tenodesis. CONCLUSION: There is poor agreement between contemporary surgeons in the classification and treatment of SLAP lesions. The age of the patient appears to play a significant factor in the surgeons' deciding to treat a SLAP lesion with repair vs. biceps tenodesis.

Sensory Distribution of the Lateral Cutaneous Nerve of Forearm After Ultrasound-Guided Block: Potential Implications for Thumb-Base Surgery.

Surgery of the wrist and hand commonly involves regional anesthesia of the median nerve and superficial radial nerve within the forearm. In this sonographic study, the contribution of the lateral cutaneous nerve of forearm (LCNF) to thumb cutaneous sensation was studied. Patients scheduled for thumb suspension arthroplasty (n = 35) were examined by ultrasound, with LCNF, median nerve, and superficial radial nerve identified. A single nerve was then injected with local anesthetic, and the area of cutaneous sensory loss mapped at 15 minutes. The remaining 2 nerves were then blocked for progression to theater. In 15 patients, the LCNF was blocked first at the antecubital fossa, where it was located posterior to the cephalic vein 9.1 (1.6) mm distal to the interepicondylar line. Bifurcation occurred further distally, 18 (2.6) mm from the interepicondylar line. In 14 of 15 cases, LCNF sensory distribution extended to the thumb base, 8.3 (7.8) mm distal to the radiocarpal joint. This study has demonstrated the LCNF to innervate the thumb base, indicating neural blockade of this nerve may be required for surgery of the basal thumb joint.

Interobserver and intraobserver variability of glenoid track measurements.

BACKGROUND: A method of assessing combined glenoid and humeral bone loss in traumatic shoulder instability with an associated treatment protocol was recently published. The aim of this study was to investigate its reliability and reproducibility. METHODS: Seventy-one patients with unilateral anteroinferior shoulder instability underwent computed tomography scans, from which 3-dimensional images were derived. En face views of both glenoid fossae and with 3 views of the humeral head were provided to 4 assessors to determine interobserver reliability. From these measurements, the shoulder was assigned a treatment classification. Two observers repeated their assessments 1 month later to determine intraobserver reliability. For each measurement, the mean coefficient of variability was calculated. RESULTS: Assessment of glenoid bone loss showed good interobserver (4 observers agreeing in 90.1% of cases) and also good intraobserver agreement (94% and 96%). There was a poor level of interobserver reliability regarding the on-track or off-track classification (72%). Intraobserver reliability for this measurement was less variable (90% and 80%). There was a poor level of agreement between observers (65%) regarding treatment classification. The coefficient of variability for the Hill-Sachs lesion measured 19.2%, indicating a high level of variability for this measurement compared with <4% for all other measures. CONCLUSION: Linear bone loss on the glenoid can be measured reliably and reproducibly; however, evaluation of Hill-Sachs lesions demonstrates a high level of variability, and poor interobserver reliability.

Latissimus Dorsi and Teres Major Tendon Avulsions in Cricketers: A Case Series and Literature Review.

INTRODUCTION: Acute latissimus dorsi tendon injuries are uncommon, having not previously been described in cricketers. The leg spinner's stock ball bowling technique and the fast bowler's back-of-the-hand slow ball, which is used much more widely in T20 cricket, produce a significant eccentric contraction load on the latissimus dorsi muscle. METHODOLOGY: A retrospective review of a case series of acute latissimus dorsi tendon injuries in 3 elite cricketers (2 fast bowlers and a leg-spin bowler). We compare the outcomes using patient-rated scales and objective strength testing. Two patients underwent operative repair and had excellent outcomes. One of the nonoperatively managed patients had mild ongoing symptoms at 7 months. DISCUSSION: An associated injury to teres major did not affect the outcome of this injury. Operative repair is a viable alternative and may produce better outcomes in cricketers. CONCLUSION: The short T20 form of cricket has lead to an increase in the number of back-of-the-hand slow balls, a risk factor for Latissimus injury, whereas leg-spin bowling is another risk.

A Rare Case of Bipolar Clavicle Fracture.

Segmental or bipolar fractures of the clavicle generally refer to a concomitant ipsilateral distal clavicle and midshaft clavicle fracture. These injuries are exceedingly rare and are generally secondary to higher energy injuries. We report a case of a 38-year-old male who sustained a left bipolar clavicle fracture after falling from a push bike while riding recreationally which unusually involved the medial and lateral ends of the clavicle and not the midshaft as previously reported in other patients. The patient's exact fracture configuration was not immediately apparent highlighting the need for careful examination of the whole clavicle in order to not miss a bipolar fracture.

Catastrophic failure of a low profile metal-backed glenoid component after total shoulder arthroplasty.

CONTEXT: The longevity of the glenoid component in total shoulder arthroplasty (TSA) continues to be problematic. All polyethylene glenoid components have been most widely used, but loosening rates with time and the need for revision has resulted in high-profile metal-backed components with the potential for a more stable prosthesis bone interface and liner exchange. High revision rates in the high profile metal backed designs led us to evaluate a low profile metal backed component. AIMS: To examine the rate and mode of failure of a TSA in a single surgeon consecutive series that has been identified by the Australian National Joint Replacement Registry to have a higher than anticipated rate of revision. MATERIALS AND METHODS: This is a single surgeon retrospective consecutive series of 51 arthroplasties undertaken in 50 patients (18 males and 32 females) with an average age of 70.4 ears (range 51-90) and mean follow-up of 5.5 years (range 3.7-8.1). RESULTS: We observed a very high (29%) rate of revision of the metal-backed glenoid components in this series. The primary mode of failure was glenoid baseplate nonintegration which with a well-fixed central cage screw led to bone resorption and implant breakage or disassembly. CONCLUSION: Analysis of the mode of failure of implants identified by robust registries is essential for the development of new prostheses and the pursuit of prosthesis longevity. This low profile metal backed prosthesis has been withdrawn, but without a published mechanism of failure. We feel that any prosthesis withdrawal should be accompanied by appropriate published mechanisms to prevent future component design errors based on similar design problems.

Use of a Bone Graft Drill Harvester to Create the Fenestration During Arthroscopic Ulnohumeral Arthroplasty.

The Outerbridge-Kashiwagi procedure, or ulnohumeral arthroplasty, was described in 1978 as a method of treating elbow arthritis by creating a fenestration in the olecranon fossa. This fenestration diminishes the likelihood of recurrent spurs in the olecranon fossa and coronoid fossa, without loss of structural bony strength. Arthroscopic techniques have now been developed to perform this procedure. We describe an efficient method of creating the fenestration between the olecranon fossa and coronoid fossa during an arthroscopic ulnohumeral arthroplasty, or Outerbridge-Kashiwagi procedure, that also reduces the amount of residual bone debris produced during the resection.

Shoulder Structure and Function Following the Modified Latarjet Procedure: A Clinical and Radiological Review.

BACKGROUND: To evaluate the clinical and radiological outcomes of the modified Latarjet procedure for traumatic, antero-inferior glenohumeral joint instability. METHODS: Case series were used with a mean follow-up of 21.3 months for clinical and radiological review and 47.2 months for recurrent instability. Shoulder function was evaluated by clinical examination and validated shoulder scales: Western Ontario Shoulder Stability Index (WOSI), Melbourne Instability Shoulder Score (MISS) and l'Insalata Shoulder Questionnaire. Shoulder structure was evaluated by computed tomography. RESULTS: Thirty-two cases were enrolled (mean age 27.0 years). One patient reported a redislocation during the follow-up period. Clinical examination revealed that the median external rotation (at 0° and 90° abduction) was reduced on the operative side by 7.5° (p < 0.01) and 10° (p < 0.001), respectively. Subjective shoulder function was good. Mean (SD) scores on the WOSI, MISS and l'Insalata scales were 78.0 (19.7), 75.8 (11.5) and 89.3 (9.9), respectively. No loss of subscapularis strength was identified (p > 0.05). Radiological evaluation revealed a mean (SD) pre-operative glenoid surface area loss of 169.5 (48.5) mm(2) reconstituted surgically by a bone block of 225.4 (73.8) mm(2). Subscapularis muscle bulk was reduced on the operative side, above the level of the muscle split (p < 0.05). CONCLUSIONS: The Latarjet procedure reliably restores lost glenoid surface area, shoulder stability, strength and function. A small loss of external rotation is expected and related to altered subscapularis anatomy.