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Bone & Joint 360
Vol. 13, Issue 6 | Pages 30 - 33
1 Dec 2024

The December 2024 Shoulder & Elbow Roundup. 360. looks at: Predicting recurrence of instability after a primary traumatic anterior shoulder dislocation; Predictors of surgery and long-term outcomes in nonoperative management of full-thickness rotator cuff tears; Reverse shoulder arthroplasty viable despite acquired acromial compromise, but higher infection risk noted; LP-PRP reduces retear rates in rotator cuff repair but shows no functional outcome advantage; Long-term clinical outcomes of arthroscopic supraspinatus tendon repair using the single anchor tension band technique – minimum five-year follow-up; Arthroscopic stabilization for anterior shoulder dislocation shows low recurrence rates regardless of prior dislocations; ORIF outperforms arthroplasty for complex radial head fractures: mid-term outcomes; Routine use of surgical helmet systems may not reduce infection risk in shoulder arthroplasty


Bone & Joint Open
Vol. 5, Issue 11 | Pages 1041 - 1048
19 Nov 2024
Delgado C Martínez-Rodríguez JM Candura D Valencia M Martínez-Catalán N Calvo E

Aims

The Bankart and Latarjet procedures are two of the most common surgical techniques to treat anterior shoulder instability with satisfactory clinical and functional outcomes. However, the outcomes in the adolescent population remain unclear, and there is no information regarding the arthroscopic Latarjet in this population. The purpose of this study was to evaluate the outcomes of the arthroscopic Bankart and arthroscopic Latarjet procedures in the management of anterior shoulder instability in adolescents.

Methods

We present a retrospective, matched-pair study of teenagers with anterior glenohumeral instability treated with an arthroscopic Bankart repair (ABR) or an arthroscopic Latarjet (AL) procedure with a minimum two-year follow-up. Preoperative demographic and clinical features, factors associated with dislocation, and complications were collected. Recurrence, defined as dislocation or subluxation, was established as the primary outcome. Clinical and functional outcomes were analyzed using objective (Rowe), and subjective (Western Ontario Shoulder Instability Index (WOSI) and Single Assessment Numeric Evaluation (SANE)) scores. Additionally, the rate of return to sport was assessed.


Bone & Joint 360
Vol. 13, Issue 5 | Pages 34 - 37
1 Oct 2024

The October 2024 Shoulder & Elbow Roundup360 looks at: Proximal humeral fractures with vascular compromise; Outcomes and challenges of revision arthroscopic rotator cuff repair: a systematic review; Evaluating treatment effectiveness for lateral elbow tendinopathy: a systematic review and network meta-analysis; Tendon transfer techniques for irreparable subscapularis tears: a comparative review; Impact of subscapularis repair in reverse shoulder arthroplasty; Isolated subscapularis tears strongly linked to shoulder pseudoparesis; Nexel and Coonrad-Morrey total elbow arthroplasties show comparable revision rates in New Zealand study; 3D MRI matches 3D CT in assessing bone loss and shoulder morphology in dislocation cases.


The Bone & Joint Journal
Vol. 106-B, Issue 10 | Pages 1165 - 1175
1 Oct 2024
Frost Teilmann J Petersen ET Thillemann TM Hemmingsen CK Olsen Kipp J Falstie-Jensen T Stilling M

Aims

The aim of this study was to evaluate the kinematics of the elbow following increasing length of the radius with implantation of radial head arthroplasties (RHAs) using dynamic radiostereometry (dRSA).

Methods

Eight human donor arms were examined by dRSA during motor-controlled flexion and extension of the elbow with the forearm in an unloaded neutral position, and in pronation and supination with and without a 10 N valgus or varus load, respectively. The elbows were examined before and after RHA with stem lengths of anatomical size, + 2 mm, and + 4 mm. The ligaments were maintained intact by using a step-cut lateral humeral epicondylar osteotomy, allowing the RHAs to be repeatedly exchanged. Bone models were obtained from CT scans, and specialized software was used to match these models with the dRSA recordings. The flexion kinematics of the elbow were described using anatomical coordinate systems to define translations and rotations with six degrees of freedom.


The Bone & Joint Journal
Vol. 106-B, Issue 10 | Pages 1141 - 1149
1 Oct 2024
Saleem J Rawi B Arnander M Pearse E Tennent D

Aims. Extensive literature exists relating to the management of shoulder instability, with a more recent focus on glenoid and humeral bone loss. However, the optimal timing for surgery following a dislocation remains unclear. There is concern that recurrent dislocations may worsen subsequent surgical outcomes, with some advocating stabilization after the first dislocation. The aim of this study was to determine if the recurrence of instability following arthroscopic stabilization in patients without significant glenoid bone loss was influenced by the number of dislocations prior to surgery. Methods. A systematic review and meta-analysis was performed using the PubMed, EMBASE, Orthosearch, and Cochrane databases with the following search terms: ((shoulder or glenohumeral) and (dislocation or subluxation) and arthroscopic and (Bankart or stabilisation or stabilization) and (redislocation or re-dislocation or recurrence or instability)). Methodology followed the PRISMA guidelines. Data and outcomes were synthesized by two independent reviewers, and papers were assessed for bias and quality. Results. Overall, 35 studies including 7,995 shoulders were eligible for analysis, with a mean follow-up of 32.7 months (12 to 159.5). The rate of post-stabilization instability was 9.8% in first-time dislocators, 9.1% in recurrent dislocators, and 8.5% in a mixed cohort. A descriptive analysis investigated the influence of recurrent instability or age in the risk of instability post-stabilization, with an association seen with increasing age and a reduced risk of recurrence post-stabilization. Conclusion. Using modern arthroscopic techniques, patients sustaining an anterior shoulder dislocation without glenoid bone loss can expect a low risk of recurrence postoperatively, and no significant difference was found between first-time and recurrent dislocators. Furthermore, high-risk cohorts can expect a low, albeit slightly higher, rate of redislocation. With the findings of this study, patients and clinicians can be more informed as to the likely outcomes of arthroscopic stabilization within this patient subset. Cite this article: Bone Joint J 2024;106-B(10):1141–1149


The Bone & Joint Journal
Vol. 106-B, Issue 10 | Pages 1100 - 1110
1 Oct 2024
Arenas-Miquelez A Barco R Cabo Cabo FJ Hachem A

Bone defects are frequently observed in anterior shoulder instability. Over the last decade, knowledge of the association of bone loss with increased failure rates of soft-tissue repair has shifted the surgical management of chronic shoulder instability. On the glenoid side, there is no controversy about the critical glenoid bone loss being 20%. However, poor outcomes have been described even with a subcritical glenoid bone defect as low as 13.5%. On the humeral side, the Hill-Sachs lesion should be evaluated concomitantly with the glenoid defect as the two sides of the same bipolar lesion which interact in the instability process, as described by the glenoid track concept. We advocate adding remplissage to every Bankart repair in patients with a Hill-Sachs lesion, regardless of the glenoid bone loss. When critical or subcritical glenoid bone loss occurs in active patients (> 15%) or bipolar off-track lesions, we should consider anterior glenoid bone reconstructions. The techniques have evolved significantly over the last two decades, moving from open procedures to arthroscopic, and from screw fixation to metal-free fixation. The new arthroscopic techniques of glenoid bone reconstruction procedures allow precise positioning of the graft, identification, and treatment of concomitant injuries with low morbidity and faster recovery. Given the problems associated with bone resorption and metal hardware protrusion, the new metal-free techniques for Latarjet or free bone block procedures seem a good solution to avoid these complications, although no long-term data are yet available.

Cite this article: Bone Joint J 2024;106-B(10):1100–1110.


The Bone & Joint Journal
Vol. 106-B, Issue 10 | Pages 1111 - 1117
1 Oct 2024
Makaram NS Becher H Oag E Heinz NR McCann CJ Mackenzie SP Robinson CM

Aims. The risk factors for recurrent instability (RI) following a primary traumatic anterior shoulder dislocation (PTASD) remain unclear. In this study, we aimed to determine the rate of RI in a large cohort of patients managed nonoperatively after PTASD and to develop a clinical prediction model. Methods. A total of 1,293 patients with PTASD managed nonoperatively were identified from a trauma database (mean age 23.3 years (15 to 35); 14.3% female). We assessed the prevalence of RI, and used multivariate regression modelling to evaluate which demographic- and injury-related factors were independently predictive for its occurrence. Results. The overall rate of RI at a mean follow-up of 34.4 months (SD 47.0) was 62.8% (n = 812), with 81.0% (n = 658) experiencing their first recurrence within two years of PTASD. The median time for recurrence was 9.8 months (IQR 3.9 to 19.4). Independent predictors increasing risk of RI included male sex (p < 0.001), younger age at PTASD (p < 0.001), participation in contact sport (p < 0.001), and the presence of a bony Bankart (BB) lesion (p = 0.028). Greater tuberosity fracture (GTF) was protective (p < 0.001). However, the discriminative ability of the resulting predictive model for two-year risk of RI was poor (area under the curve (AUC) 0.672). A subset analysis excluding identifiable radiological predictors of BB and GTF worsened the predictive ability (AUC 0.646). Conclusion. This study clarifies the prevalence and risk factors for RI following PTASD in a large, unselected patient cohort. Although these data permitted the development of a predictive tool for RI, its discriminative ability was poor. Predicting RI remains challenging, and as-yet-undetermined risk factors may be important in determining the risk. Cite this article: Bone Joint J 2024;106-B(10):1111–1117


Bone & Joint Open
Vol. 5, Issue 7 | Pages 570 - 580
10 Jul 2024
Poursalehian M Ghaderpanah R Bagheri N Mortazavi SMJ

Aims

To systematically review the predominant complication rates and changes to patient-reported outcome measures (PROMs) following osteochondral allograft (OCA) transplantation for shoulder instability.

Methods

This systematic review, following PRISMA guidelines and registered in PROSPERO, involved a comprehensive literature search using PubMed, Embase, Web of Science, and Scopus. Key search terms included “allograft”, “shoulder”, “humerus”, and “glenoid”. The review encompassed 37 studies with 456 patients, focusing on primary outcomes like failure rates and secondary outcomes such as PROMs and functional test results.


Bone & Joint 360
Vol. 13, Issue 3 | Pages 31 - 34
3 Jun 2024

The June 2024 Shoulder & Elbow Roundup. 360. looks at: Reverse versus anatomical total shoulder replacement for osteoarthritis? A UK national picture; Acute rehabilitation following traumatic anterior shoulder dislocation (ARTISAN): pragmatic, multicentre, randomized controlled trial; acid for rotator cuff repair: a systematic review and meta-analysis of randomized controlled trials; Metal or ceramic humeral head total shoulder arthroplasty: an analysis of data from the National Joint Registry; Platelet-rich plasma has better results for long-term functional improvement and pain relief for lateral epicondylitis: a systematic review and meta-analysis of randomized controlled trials; Quantitative fatty infiltration and 3D muscle volume after nonoperative treatment of symptomatic rotator cuff tears: a prospective MRI study of 79 patients; Locking plates for non-osteoporotic proximal humeral fractures in the long term; A systematic review of the treatment of primary acromioclavicular joint osteoarthritis


Bone & Joint 360
Vol. 13, Issue 2 | Pages 30 - 33
1 Apr 2024

The April 2024 Shoulder & Elbow Roundup. 360. looks at: Acute rehabilitation following traumatic anterior shoulder dislocation (ARTISAN): pragmatic, multicentre, randomized controlled trial; Prevalence and predisposing factors of neuropathic pain in patients with rotator cuff tears; Are two plates better than one? The clavicle fracture reimagined; A single cell atlas of frozen shoulder capsule identifies features associated with inflammatory fibrosis resolution; Complication rates and deprivation go hand in hand with total shoulder arthroplasty; Longitudinal instability injuries of the forearm; A better than “best-fit circle” method for glenoid bone loss assessment; 3D supraspinatus muscle volume and intramuscular fatty infiltration after arthroscopic rotator cuff repair


The Bone & Joint Journal
Vol. 106-B, Issue 3 Supple A | Pages 74 - 80
1 Mar 2024
Heckmann ND Plaskos C Wakelin EA Pierrepont JW Baré JV Shimmin AJ

Aims

Excessive posterior pelvic tilt (PT) may increase the risk of anterior instability after total hip arthroplasty (THA). The aim of this study was to investigate the changes in PT occurring from the preoperative supine to postoperative standing position following THA, and identify factors associated with significant changes in PT.

Methods

Supine PT was measured on preoperative CT scans and standing PT was measured on preoperative and one-year postoperative standing lateral radiographs in 933 patients who underwent primary THA. Negative values indicate posterior PT. Patients with > 13° of posterior PT from preoperative supine to postoperative standing (ΔPT ≤ -13°) radiographs, which corresponds to approximately a 10° increase in functional anteversion of the acetabular component, were compared with patients with less change (ΔPT > -13°). Logistic regression analysis was used to assess preoperative demographic and spinopelvic parameters predictive of PT changes of ≤ -13°. The area under receiver operating characteristic curve (AUC) determined the diagnostic accuracy of the predictive factors.


Bone & Joint 360
Vol. 13, Issue 1 | Pages 26 - 29
1 Feb 2024

The February 2024 Shoulder & Elbow Roundup. 360. looks at: Does indomethacin prevent heterotopic ossification following elbow fracture fixation?; Arthroscopic capsular shift in atraumatic shoulder joint instability; Ultrasound-guided lavage with corticosteroid injection versus sham; Combined surgical and exercise-based interventions following primary traumatic anterior shoulder dislocation: a systematic review and meta-analysis; Are vascularized fibula autografts a long-lasting reconstruction after intercalary resection of the humerus for primary bone tumours?; Anatomical versus reverse total shoulder arthroplasty with limited forward elevation; Tension band or plate fixation for simple displaced olecranon fractures?; Is long-term follow-up and monitoring in shoulder and elbow arthroplasty needed?


Bone & Joint 360
Vol. 12, Issue 6 | Pages 31 - 34
1 Dec 2023

The December 2023 Shoulder & Elbow Roundup360 looks at: Clavicle fractures: is the evidence changing practice?; Humeral shaft fractures, and another meta-analysis…let’s wait for the trials now!; Hemiarthroplasty or total elbow arthroplasty for distal humeral fractures…what does the registry say?; What to do with a first-time shoulder dislocation?; Deprivation indices and minimal clinically important difference for patient-reported outcomes after arthroscopic rotator cuff repair; Prospective randomized clinical trial of arthroscopic repair versus debridement for partial subscapularis tears; Long-term follow-up following closed reduction and early movement for simple dislocation of the elbow; Sternoclavicular joint reconstruction for traumatic acute and chronic anterior and posterior instability.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_18 | Pages 13 - 13
1 Dec 2023
Elgendy M Makki D White C ElShafey A
Full Access

Introduction. We aim to assess whether radiographic characteristics of the greater tuberosity fragment can predict rotator cuff tears inpatients with anterior shoulder dislocations combined with an isolated fracture of the greater tuberosity. Methods. A retrospective single-centre case series of 61 consecutive patients that presented with anterior shoulder dislocations combined with an isolated fracture of the greater tuberosity between January 2018 and July 2022. Inclusion criteria: patients with atraumatic anterior shoulder dislocation associated with an isolated fracture of the greater tuberosity with a minimum follow-up of 3-months. Exclusion criteria: patients with other fractures of the proximal humerus or glenoid. Rotator cuff tears were diagnosed using magnetic resonance or ultrasound imaging. Greater tuberosity fragment size and displacement was calculated on plain radiographs using validated methods. Results. The case series was composed of 22 men and 39 women with a mean age of 65 years (29 - 91 years). The mean follow-up was 15months and median follow up 8.5 months (3 – 60 months). A rotator cuff tear was diagnosed in 14 patients (16%) and involved the supraspinatus (13), infraspinatus (4) and subscapularis (2). Full-thickness tears occurred in 6 patients and partial-thickness tears in 8patients. The mean time from initial injury to rotator cuff tear diagnosis was 5 months (2 – 22 months). The mean greater tuberosity fragment length was 23.4 mm in rotator cuff tear patients versus 32.6 mm in those without a tear (p = 0.006, CI: -15 - -2). The mean greater tuberosity. fragment width was 11.1 mm in rotator cuff tear patients versus 17.8 mm in those without a tear (p = 0.0004, CI: -10 - -2). There was no significant difference in the super inferior and anteroposterior fragment displacement between the two groups. Conclusion. In patients with shoulder dislocations combined with an isolated fracture of the greater tuberosity, rotator cuff tears are associated with a smaller sized greater tuberosity fragment


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_15 | Pages 19 - 19
7 Nov 2023
Hackney R Toland G Crosbie G Mackenzi S Clement N Keating J
Full Access

A fracture of the tuberosity is associated with 16% of anterior glenohumeral dislocations. Manipulation of these injuries in the emergency department is safe with less than 1% risk of fracture propagation. However, there is a risk of associated neurological injury, recurrent instability and displacement of the greater tuberosity fragment. The risks and outcomes of these complications have not previously been reported. The purpose of this study was to establish the incidence and outcome of complications associated with this pattern of injury. We reviewed 339 consecutive glenohumeral dislocations with associated greater tuberosity fractures from a prospective trauma database. Documentation and radiographs were studied and the incidence of neurovascular compromise, greater tuberosity fragment migration and intervention and recurrent instability recorded. The mean age was 61 years (range, 18–96) with a female preponderance (140:199 male:female). At presentation 24% (n=78) patients had a nerve injury, with axillary nerve being most common (n=43, 55%). Of those patients with nerve injuries 15 (19%) did not resolve. Greater tuberosity displacement >5mm was observed in 36% (n=123) of patients with 40 undergoing acute surgery, the remainder did not due to comorbidities or patient choice. Persistent displacement after reduction accounted for 60 cases, later displacement within 6 weeks occurred in 63 patients. Recurrent instability occurred in 4 (1%) patients. Patient reported outcomes were poor with average EQ5D being 0.73, QDASH score of 16 and Oxford Shoulder Score of 41. Anterior glenohumeral dislocation with associated greater tuberosity fracture is common with poor long term patient reported outcomes. Our results demonstrate there is a high rate of neurological deficits at presentation with the majority resolving spontaneously. Recurrent instability is rare. Late tuberosity fragment displacement occurs in 18% of patients and regular follow-up for 6 weeks is recommended to detect this


Bone & Joint Research
Vol. 12, Issue 9 | Pages 571 - 579
20 Sep 2023
Navacchia A Pagkalos J Davis ET

Aims

The aim of this study was to identify the optimal lip position for total hip arthroplasties (THAs) using a lipped liner. There is a lack of consensus on the optimal position, with substantial variability in surgeon practice.

Methods

A model of a THA was developed using a 20° lipped liner. Kinematic analyses included a physiological range of motion (ROM) analysis and a provocative dislocation manoeuvre analysis. ROM prior to impingement was calculated and, in impingement scenarios, the travel distance prior to dislocation was assessed. The combinations analyzed included nine cup positions (inclination 30-40-50°, anteversion 5-15-25°), three stem positions (anteversion 0-15-30°), and five lip orientations (right hip 7 to 11 o’clock).


The Bone & Joint Journal
Vol. 105-B, Issue 4 | Pages 389 - 399
15 Mar 2023
Makaram NS Nicholson JA Yapp LZ Gillespie M Shah CP Robinson CM

Aims

The open Latarjet procedure is a widely used treatment for recurrent anterior instability of the shoulder. Although satisfactory outcomes are reported, factors which influence a patient’s experience are poorly quantified. The aim of this study was to evaluate the effect of a range of demographic factors and measures of the severity of instability on patient-reported outcome measures in patients who underwent an open Latarjet procedure at a minimum follow-up of two years.

Methods

A total of 350 patients with anterior instability of the shoulder who underwent an open Latarjet procedure between 2005 and 2018 were reviewed prospectively, with the collection of demographic and psychosocial data, preoperative CT, and complications during follow-up of two years. The primary outcome measure was the Western Ontario Shoulder Instability Index (WOSI), assessed preoperatively, at two years postoperatively, and at mid-term follow-up at a mean of 50.6 months (SD 24.8) postoperatively. The secondary outcome measure was the abbreviated version of the Disabilities of the Arm, Shoulder and Hand (QuickDASH) score. The influence of the demographic details of the patients, measurements of the severity of instability, and the complications of surgery were assessed in a multivariate analysis.


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_2 | Pages 90 - 90
10 Feb 2023
Burn P
Full Access

Polyimide (MP-1, MMATech, Haifa, Israel), is a high performance aerospace thermoplastic used for its lubricity, stability, inertness and radiation resistance. A wear resistant thin robust bearing is needed for total hip arthroplasty (THR). After independent laboratory testing, in 2006, the author used the material as a bearing in two Reflection (Smith and Nephew, USA) hip surgeries. The first, a revision for polyethylene wear, survives with no evidence of wear, noise, new osteolysis or complications related to the MP-1 bearing after 16 yrs. The second donated his asymptomatic MP-1 hip at 6.5yrs for post-mortem examination. There were no osteoclasts, cellular reaction bland in contrast to that of polyethylene. In 2013 a clinical study with ethical committee approval was started using a Biolox Delta (Ceramtec, Germany) head against a polyimide liner in 97 patients. MMATech sold all liners, irradiated: steam 52:45. Sixteen were re-machined in New Zealand. Acetabular shells were Delta PF (LIMA, Italy). The liner locked by taper. The cohort consisted of 46:51 M:F, and ages 43 to 85, mean 65. Ten received cemented stems. For contralateral surgery, a ceramic or polyethylene liner was used. Initial patients were lower demand, later, more active patients, mountain-biking and running. All patients have on-going follow up, including MP-1 liner revision cases. There has been no measurable wear, or osteolysis around the acetabular components using weight-bearing radiographs. Squeaking within the first 6 weeks was noted in 39 number of cases and subtle increase in palpable friction, (passive rotation at 50 degrees flexion), but then disappeared. There were 6 revisions, four of which were related to cementless Stemsys implants (Evolutis, Italy) fixed distally with proximal linear lucencies in Gruen zones 1 and 7, and 2 and 6. No shells were revised and MP-1 liners were routinely changed to ceramic or polyethylene. The liners showed no head contact at the apex, with highly polished contact areas. There were no deep or superficial infections, but one traumatic anterior dislocation at 7 years associated with 5 mm subsidence of a non-collared stem. The initial squeaking and increased friction was due to the engineering of the liner / shell composite as implanted, not allowing adequate clearance for fluid film lubrication and contributed to by shell distortion during impaction. The revised bearings were “equatorial” rather than polar, and with lack of wear or creep this never fully resolved. Where the clearance was better, function was normal. The “slow” utilization was due to my ongoing concern with clearances not being correct. The revision of 4 Stemsys stems, tribology issues may have contributed, but non “MP-1” / Stemsys combinations outside this study have shown the same response, thought to be due to de-bonding of the hydroxyapatite coating. With correct engineering and clearances, a 3.6 mm thick MP-1 bearing, a surface Ra<0.5, steam sterilized, shows no appreciable wear, and with confidence, can be used as a high performance THR bearing


Bone & Joint Research
Vol. 11, Issue 11 | Pages 814 - 825
14 Nov 2022
Ponkilainen V Kuitunen I Liukkonen R Vaajala M Reito A Uimonen M

Aims

The aim of this systematic review and meta-analysis was to gather epidemiological information on selected musculoskeletal injuries and to provide pooled injury-specific incidence rates.

Methods

PubMed (National Library of Medicine) and Scopus (Elsevier) databases were searched. Articles were eligible for inclusion if they reported incidence rate (or count with population at risk), contained data on adult population, and were written in English language. The number of cases and population at risk were collected, and the pooled incidence rates (per 100,000 person-years) with 95% confidence intervals (CIs) were calculated by using either a fixed or random effects model.


The Bone & Joint Journal
Vol. 104-B, Issue 10 | Pages 1180 - 1188
1 Oct 2022
Qu H Mou H Wang K Tao H Huang X Yan X Lin N Ye Z

Aims. Dislocation of the hip remains a major complication after periacetabular tumour resection and endoprosthetic reconstruction. The position of the acetabular component is an important modifiable factor for surgeons in determining the risk of postoperative dislocation. We investigated the significance of horizontal, vertical, and sagittal displacement of the hip centre of rotation (COR) on postoperative dislocation using a CT-based 3D model, as well as other potential risk factors for dislocation. Methods. A total of 122 patients who underwent reconstruction following resection of periacetabular tumour between January 2011 and January 2020 were studied. The risk factors for dislocation were investigated with univariate and multivariate logistic regression analysis on patient-specific, resection-specific, and reconstruction-specific variables. Results. The dislocation rate was 13.9% (n = 17). The hip COR was found to be significantly shifted anteriorly and inferiorly in most patients in the dislocation group compared with the non-dislocation group. Three independent risk factors were found to be related to dislocation: resection of gluteus medius (odds ratio (OR) 3.68 (95% confidence interval (CI) 1.24 to 19.70); p = 0.039), vertical shift of COR > 18 mm (OR 24.8 (95% CI 6.23 to 128.00); p = 0.001), and sagittal shift of COR > 20 mm (OR 6.22 (95% CI 1.33 to 32.2); p = 0.026). Conclusion. Among the 17 patients who dislocated, 70.3% (n = 12) were anterior dislocations. Three independent risk factors were identified, suggesting the importance of proper restoration of the COR and the role of the gluteus medius in maintaining hip joint stability. Cite this article: Bone Joint J 2022;104-B(10):1180–1188