A simple procedure of using a Smillie knife to release the lateral patellar retinaculum and the capsule in the unstable patella syndrome is described. The syndrome includes recurrent dislocation, recurrent subluxation and acute dislocation of the patella. Arthroscopy, to exclude any other pathology such as chondromalacia patellae, is performed before proceeding to closed lateral release. The results of this procedure are as good as those after more major surgical procedures. In a small percentage of patients a second operation such as tibial tubercle transfer or patellectomy may be necessary, especially in patients with an underlying congenital abnormality; but in many patients this type of major surgery has proved unnecessary.

1. Eighty-five patients have been studied soon after a ligamentous injury at the foot or ankle. These patients were treated in one of three ways, and in fifty-six patients the results were evaluated six to fifteen months after injury.

2. It is concluded: a) that ligamentous injuries at the foot and ankle frequently produce a proprioceptive deficit affecting the muscles of the injured leg; b) that such a deficit is responsible for the symptom of "giving way" of the foot; and c) that the incidence of both the proprioceptive deficit and the symptom of "giving way" can substantially be reduced by treatment after injury with the coordination exercises described in this study.

3. The mechanism of production of the proprioceptive defect is discussed.

In this study we evaluated whether the Instability Severity Index Score (ISIS) and the Western Ontario Shoulder Instability Index (WOSI) could detect those patients at risk of failure following arthroscopic Bankart repair. Between April 2008 and June 2010, the ISIS and WOSI were recorded pre-operatively in 110 patients (87 male, 79%) with a mean age of 25.1 years (16 to 61) who underwent this procedure for recurrent anterior glenohumeral instability.

A telephone interview was performed two-years post-operatively to determine whether patients had experienced a recurrent dislocation and whether they had returned to pre-injury activity levels. In all, six (5%) patients had an ISIS > 6 points (0 to 9). Of 100 (91%) patients available two years post-operatively, six (6%) had a recurrent dislocation, and 28 (28%) did not return to pre-injury activity. No patient who dislocated had an ISIS > 6 (p = 1.0). There was no difference in the mean pre-operative WOSI in those who had a re-dislocation and those who did not (p = 0.99). The pre-operative WOSI was significantly lower (p = 0.02) in those who did not return to pre-injury activity, whereas the ISIS was not associated with return to pre-injury activity (p = 0.13).

In conclusion, neither the pre-operative ISIS nor WOSI predicted recurrent dislocation within two years of arthroscopic Bankart repair. Patients with a lower pre-operative WOSI were less likely to return to pre-injury activity.

Cite this article: Bone Joint J 2014; 96-B:1688–92.

We describe a patient with multiple sclerosis (MS), who developed recurrent dislocations after total knee arthroplasty. She had both knees replaced using similar mobile-bearing knee prostheses, but the outcome was worse in the leg which was more severely affected with MS.

There have been differing descriptions of the anterolateral structures of the knee, and not all have been named or described clearly. The aim of this study was to provide a clear anatomical interpretation of these structures. We dissected 40 fresh-frozen cadaveric knees to view the relevant anatomy and identified a consistent structure in 33 knees (83%); we termed this the anterolateral ligament of the knee. This structure passes antero-distally from an attachment proximal and posterior to the lateral femoral epicondyle to the margin of the lateral tibial plateau, approximately midway between Gerdy’s tubercle and the head of the fibula. The ligament is superficial to the lateral (fibular) collateral ligament proximally, from which it is distinct, and separate from the capsule of the knee. In the eight knees in which it was measured, we observed that the ligament was isometric from 0° to 60° of flexion of the knee, then slackened when the knee flexed further to 90° and was lengthened by imposing tibial internal rotation.

Cite this article: Bone Joint J 2014;96-B:325–31.

From 1984 to 1995, 68 ankylosed elbows and 11 which were unstable after trauma were replaced in India by Baksi sloppy hinge prostheses. The mean age of the patients was 28.6 years (17 to 70) and the mean follow-up 9.6 years (2 to 13.5).

Of the 68 ankylosed elbows, 59 (87%) regained a mean arc of painless movement of 88.5° (27 to 115). The mean improvement of supination was 24° and of pronation 16.5°. There were 54 good results (80%), eight fair and three poor. There were two complete failures due to infection, and one due to a broken humeral stem.

Of the 11 unstable elbows, the nine with good results had a mean arc of 125° (15 to 140) of painless stable movement, with a mean improvement in supination of 26° and of pronation of 19.5°. There was one fair result and one failure due to loosening with subsequent late infection.

There were significant complications in 14 cases with infection in seven and aseptic loosening in four. Patients with loosening or late removal of the prosthesis often retained reasonably stable elbow movement because periprosthetic fibrosis had connected the approximated bone ends, and muscle balance had been restored.

We have developed an apparatus to measure the anteroposterior stability of the knee to forces of up to 250 N, applied at 20 degrees of flexion. We measured anterior laxity at 200 N, anterior stiffness at 50 N and total laxity at +/- 200 N. A study of cadaveric knees revealed that the soft tissues surrounding the bones had a significant influence on the force-displacement curve, and emphasised that differences between injured and normal pairs of knees are much more important than the absolute values of the parameters. In 61 normal volunteers we found no significant left to right differences in anterior laxity at 200 N and anterior stiffness at 50 N. In 92 patients with unilateral anterior cruciate deficiency there were significant differences (p less than 0.0005) in anterior laxity, anterior stiffness and total laxity, the injured-normal differences averaging 6.7 mm, 1.3 N/mm, and 8.1 mm respectively.

A total of 12 epileptic patients (14 shoulders) with recurrent seizures and anterior dislocations of the shoulder underwent a Latarjet procedure and were reviewed at a mean of 8.3 years (1 to 20) post-operatively. Mean forward flexion decreased from 165° (100° to 180°) to 160° (90° to 180°) (p = 0.5) and mean external rotation from 54° (10° to 90°) to 43° (5° to 75°) (p = 0.058). The mean Rowe score was 76 (35 to 100) at the final follow-up. Radiologically, all shoulders showed a glenoid-rim defect and Hill-Sachs lesions pre-operatively. Osteo-arthritic changes of the glenohumeral joint were observed in five shoulders (36%) pre-operatively and in eight shoulders (57%) post-operatively. Re-dislocation during a seizure occurred in six shoulders (43%). Five of these patients underwent revision surgery using a bone buttress from the iliac crest and two of these patients re-dislocated due to a new seizure.

Due to the unacceptably high rate of re-dislocation after surgery in these patients, the most important means of reducing the incidence of further dislocation is the medical management of the seizures. The Latarjet procedure should be reserved for the well-controlled patient with epilepsy who has recurrent anterior dislocation of the shoulder during activities of daily living.

Ankylosing spondylitis (AS) is a progressive multisystem chronic inflammatory disorder. The hallmark of this pathological process is a progressive fusion of the zygapophyseal joints and disc spaces of the axial skeleton, leading to a rigid kyphotic deformity and positive sagittal balance. The ankylosed spine is unable to accommodate normal mechanical forces, rendering it brittle and susceptible to injury. Traumatic hyperextension injury of the cervical spine leading to atlantoaxial subluxation (AAS) in AS patients can often be fatal. We report a non-traumatic mechanism of injury in AS progressing to AAS attributable to persistent hyperextension, which resulted in fatal migration of C2 through the foramen magnum.

Cite this article: Bone Joint J 2013;95-B:206–9.

There are several methods for evaluating stability of the joint during total knee replacement (TKR). Activities of daily living demand mechanical loading to the knee joint, not only in full extension, but also in mid-flexion. The purpose of this study was to compare the varus-valgus stability throughout flexion in knees treated with either cruciate-retaining or posterior-stabilised TKR, using an intra-operative navigation technique. A total of 34 knees underwent TKR with computer navigation, during which the investigator applied a maximum varus-valgus stress to the knee while steadily moving the leg from full extension to flexion both before and after prosthetic implantation. The femorotibial angle was measured simultaneously by the navigation system at every 10° throughout the range of movement. It was found that posterior-stabilised knees had more varus-valgus laxity than cruciate-retaining knees at all angles examined, and the differences were statistically significant at 10° (p = 0.0093), 20° (p = 0.0098) and 30° of flexion (p = 0.0252).

Cite this article: Bone Joint J 2013;95-B:493–7.

Aims. The current evidence comparing the two most common approaches for reverse total shoulder arthroplasty (rTSA), the deltopectoral and anterosuperior approach, is limited. This study aims to compare the rate of loosening, instability, and implant survival between the two approaches for rTSA using data from the Dutch National Arthroplasty Registry with a minimum follow-up of five years. Methods. All patients in the registry who underwent a primary rTSA between January 2014 and December 2016 using an anterosuperior or deltopectoral approach were included, with a minimum follow-up of five years. Cox and logistic regression models were used to assess the association between the approach and the implant survival, instability, and glenoid loosening, independent of confounders. Results. In total, 3,902 rTSAs were included. A deltopectoral approach was used in 54% (2,099/3,902) and an anterosuperior approach in 46% (1,803/3,902). Overall, the mean age in the cohort was 75 years (50 to 96) and the most common indication for rTSA was cuff tear arthropathy (35%; n = 1,375), followed by osteoarthritis (29%; n = 1,126), acute fracture (13%; n = 517), post-traumatic sequelae (10%; n = 398), and an irreparable cuff rupture (5%; n = 199). The two high-volume centres performed the anterosuperior approach more often compared to the medium- and low-volume centres (p < 0.001). Of the 3,902 rTSAs, 187 were revised (5%), resulting in a five-year survival of 95.4% (95% confidence interval 94.7 to 96.0; 3,137 at risk). The most common reason for revision was a periprosthetic joint infection (35%; n = 65), followed by instability (25%; n = 46) and loosening (25%; n = 46). After correcting for relevant confounders, the revision rate for glenoid loosening, instability, and the overall implant survival did not differ significantly between the two approaches (p = 0.494, p = 0.826, and p = 0.101, respectively). Conclusion. The surgical approach used for rTSA did not influence the overall implant survival or the revision rate for instability or glenoid loosening. Cite this article: Bone Joint J 2023;105-B(9):1000–1006

Injury to the triangular fibrocartilage complex (TFCC) may result in ulnar wrist pain with or without instability. One component of the TFCC, the radioulnar ligaments, serve as the primary soft-tissue stabilizer of the distal radioulnar joint (DRUJ). Tears or avulsions of its proximal, foveal attachment are thought to be associated with instability of the DRUJ, most noticed during loaded pronosupination. In the absence of detectable instability, injury of the foveal insertion of the radioulnar ligaments may be overlooked. While advanced imaging techniques such as MRI and radiocarpal arthroscopy are well-suited for diagnosing central and distal TFCC tears, partial and complete foveal tears without instability may be missed without a high degree of suspicion. While technically challenging, DRUJ arthroscopy provides the most accurate method of detecting foveal abnormalities. In this annotation the spectrum of foveal injuries is discussed and a modified classification scheme is proposed. Cite this article: Bone Joint J 2023;105-B(1):5–10

The October 2023 Shoulder & Elbow Roundup. 360. looks at: Arthroscopic capsular shift surgery in patients with atraumatic shoulder joint instability: a randomized, placebo-controlled trial; Superior capsular reconstruction partially restores native glenohumeral loads in a dynamic model; Gene expression in glenoid articular cartilage varies in acute instability, chronic instability, and osteoarthritis; Intra-articular injection versus interscalene brachial plexus block for acute-phase postoperative pain management after arthroscopic shoulder surgery; Level of pain catastrophizing rehab in subacromial impingement: secondary analyses from a pragmatic randomized controlled trial (the SExSI Trial); Anterosuperior versus deltopectoral approach for primary reverse total shoulder arthroplasty: a study of 3,902 cases from the Dutch National Arthroplasty Registry with a minimum follow-up of five years; Assessment of progression and clinical relevance of stress-shielding around press-fit radial head arthroplasty: a comparative study of two implants; A number of modifiable and non-modifiable factors increase the risk for elbow medial ulnar collateral ligament injury in baseball players: a systematic review

Aims. The prevalence of osteoarthritis (OA) associated with instability of the shoulder ranges between 4% and 60%. Articular cartilage is, however, routinely assessed in these patients using radiographs or scans (2D or 3D), with little opportunity to record early signs of cartilage damage. The aim of this study was to assess the prevalence and localization of chondral lesions and synovial damage in patients undergoing arthroscopic surgery for instablility of the shoulder, in order to classify them and to identify risk factors for the development of glenohumeral OA. Methods. A total of 140 shoulders in 140 patients with a mean age of 28.5 years (15 to 55), who underwent arthroscopic treatment for recurrent glenohumeral instability, were included. The prevalence and distribution of chondral lesions and synovial damage were analyzed and graded into stages according to the division of the humeral head and glenoid into quadrants. The following factors that might affect the prevalence and severity of chondral damage were recorded: sex, dominance, age, age at the time of the first dislocation, number of dislocations, time between the first dislocation and surgery, preoperative sporting activity, Beighton score, type of instability, and joint laxity. Results. A total of 133 patients (95%) had synovial or chondral lesions. At the time of surgery, shoulders were graded as having mild, moderate, and severe OA in 55 (39.2%), 72 (51.4%), and six (4.2%) patients, respectively. A Hill-Sachs lesion and fibrillation affecting the anteroinferior glenoid cartilage were the most common findings. There was a significant positive correlation between the the severity of the development of glenohumeral OA and the patient’s age, their age at the time of the first dislocation, and the number of dislocations (p = 0.004, p = 0.011, and p = 0.031, respectively). Conclusion. Synovial inflammation and chondral damage associated with instability of the shoulder are more prevalent than previously reported. The classification using quadrants gives surgeons more information about the chondral damage, and could explain the pattern of development of glenohumeral OA after stabilization of the shoulder. As the number of dislocations showed a positive correlation with the development of OA, this might be an argument for early stabilization. Cite this article: Bone Joint J 2024;106-B(10):1125–1132

Aims. Knowledge on total knee arthroplasties (TKAs) in patients with a history of poliomyelitis is limited. This study compared implant survivorship and clinical outcomes among affected and unaffected limbs in patients with sequelae of poliomyelitis undergoing TKAs. Methods. A retrospective review of our total joint registry identified 94 patients with post-polio syndrome undergoing 116 primary TKAs between January 2000 and December 2019. The mean age was 70 years (33 to 86) with 56% males (n = 65) and a mean BMI of 31 kg/m. 2. (18 to 49). Rotating hinge TKAs were used in 14 of 63 affected limbs (22%), but not in any of the 53 unaffected limbs. Kaplan-Meier survivorship analyses were completed. The mean follow-up was eight years (2 to 19). Results. The ten-year survivorship free from revision was 91% (95% confidence interval (CI) 81 to 100) in affected and 84% (95% CI 68 to 100) in unaffected limbs. There were six revisions in affected limbs: three for periprosthetic femoral fractures and one each for periprosthetic joint infection (PJI), patellar clunk syndrome, and instability. Unaffected limbs were revised in four cases: two for instability and one each for PJI and tibial component loosening. The ten-year survivorship free from any reoperation was 86% (95% CI 75 to 97) and 80% (95% CI 64 to 99) in affected and unaffected limbs, respectively. There were three additional reoperations among affected and two in unaffected limbs. There were 12 nonoperative complications, including four periprosthetic fractures. Arthrofibrosis occurred in five affected (8%) and two unaffected limbs (4%). Postoperative range of motion decreased with 31% achieving less than 90° knee flexion by five years. Conclusion. TKAs in post-polio patients are complex cases associated with instability, and one in four require constraint on the affected side. Periprosthetic fracture was the main mode of failure. Arthrofibrosis rates were high and twice as frequent in affected limbs. Cite this article: Bone Joint J 2023;105-B(6):635–640

Recognized anatomic variations that lead to patella instability include patella alta and trochlea dysplasia. Lateralization of the extensor mechanism relative to the trochlea is often considered to be a contributing factor; however, controversy remains as to the degree this contributes to instability and how this should be measured. As the tibial tuberosity-trochlear groove (TT-TG) is one of most common imaging measurements to assess lateralization of the extensor mechanism, it is important to understand its strengths and weaknesses. Care needs to be taken while interpreting the TT-TG value as it is affected by many factors. Medializing tibial tubercle osteotomy is sometimes used to correct the TT-TG, but may not truly address the underlying anatomical problem. This review set out to determine whether the TT-TG distance sufficiently summarizes the pathoanatomy, and if this assists with planning of surgery in patellar instability. Cite this article: Bone Jt Open 2022;3(3):268–274