Risk of prolonged postoperative opioid use after elective shoulder replacement: a nationwide cohort study of 5,660 patients from the Danish Shoulder Arthroplasty Registry.

BACKGROUND AND PURPOSE: Several studies from the United States report an increased risk of prolonged opioid use after shoulder replacement. We aimed to determine the incidence and risk factors of prolonged opioid use after elective shoulder replacement in a nationwide Danish population. METHODS: All primary elective shoulder arthroplasties reported to the Danish Shoulder Arthroplasty Registry (DSR) from 2004 to 2020 were screened for eligibility. Data on potential risk factors was retrieved from the DSR and the National Danish Patient Registry while data on medication was retrieved from the Danish National Health Service Prescription Database. Prolonged opioid use was defined as 1 or more dispensed prescriptions on and 90 days after date of surgery (Q1) and subsequently 1 or more dispensed prescriptions 91-180 days after surgery (Q2). Preoperative opioid use was defined as 1 or more dispensed prescriptions 90 days before surgery. Logistic regression models were used to estimate risk factors for prolonged opioid use. RESULTS: We included 5,660 patients. Postoperatively 1,584 (28%) patients were dispensed 1 or more prescriptions in Q1 and Q2 and were classified as prolonged opioid users. Among the 2,037 preoperative opioid users and the 3,623 non-opioid users, 1,201 (59%) and 383 (11%) respectively were classified as prolonged users. Preoperative opioid use, female sex, alcohol abuse, previous surgery, high Charlson Comorbidity index, and preoperative use of either antidepressants, antipsychotics, or benzodiazepines were associated with increased risk of prolonged opioid use. CONCLUSION: The incidence of prolonged opioid use was 28%. Preoperative use of opioids was the strongest risk factor for prolonged opioid use, but several other risk factors were identified for prolonged opioid use.

High rate of clinically relevant improvement following anatomical total shoulder arthroplasty for glenohumeral osteoarthritis.

BACKGROUND: The minimal clinically important difference (MCID) is defined as the smallest meaningful change in a health domain that a patient would identify as important. Thus, an improvement that exceeds the MCID can be used to define a successful treatment for the individual patient. AIM: To quantify the rate of clinical improvement following anatomical total shoulder arthroplasty for glenohumeral osteoarthritis. METHODS: Patients were treated with the Global Unite total shoulder platform arthroplasty between March 2017 and February 2019 at Herlev and Gentofte Hospital, Denmark. The patients were evaluated preoperatively and 3 months, 6 months, 12 months, and 24 months postoperatively using the Western Ontario Osteoarthritis of the Shoulder index (WOOS), Oxford Shoulder Score (OSS) and Constant-Murley Score (CMS). The rate of clinically relevant improvement was defined as the proportion of patients who had an improvement 24 months postoperatively that exceeded the MCID. Based on previous literature, MCID for WOOS, OSS, and CMS were defined as 12.3, 4.3, and 12.8 respectively. RESULTS: Forty-nine patients with a Global Unite total shoulder platform arthroplasty were included for the final analysis. Mean age at the time of surgery was 66 years (range 49.0-79.0, SD: 8.3) and 65% were women. One patient was revised within the two years follow-up. The mean improvement from the preoperative assessment to the two-year follow-up was 46.1 points [95% confidence interval (95%CI): 39.7-53.3, P < 0.005] for WOOS, 18.2 points (95%CI: 15.5-21.0, P < 0.005) for OSS and 37.8 points (95%CI: 31.5-44.0, P < 0.005) for CMS. Two years postoperatively, 41 patients (87%) had an improvement in WOOS that exceeded the MCID, 45 patients (94%) had an improvement in OSS that exceeded the MCID, and 42 patients (88%) had an improvement in CMS that exceeded the MCID. CONCLUSION: Based on three shoulder-specific outcome measures we find that approximately 90% of patients has a clinically relevant improvement. This is a clear message when informing patients about their prognosis.

Low risk of postoperative ulnar nerve affection in surgically treated distal humeral fractures when the nerve is released in situ.

BACKGROUND: Adult distal humeral fractures (DHF) comprise 2%-5% of all fractures and 30% of all elbow fractures. Treatment of DHF may be technically demanding due to fracture complexity and proximity of neurovascular structures. Open reduction and internal fixation (ORIF) are often the treatment of choice, but arthroplasty is considered in case of severe comminution or in elderly patients with poor bone quality. Ulnar nerve affection following surgical treatment of distal humerus fractures is a well-recognized complication. AIM: To report the risk of ulnar nerve affection after surgery for acute DHFs. METHODS: We retrospectively identified 239 consecutive adult patients with acute DHFs who underwent surgery with ORIF, elbow hemiarthroplasty (EHA) or total elbow arthroplasty (TEA) between January 2011 and December 2019. In all cases, the ulnar nerve was released in situ without anterior transposition. We used our institutional database to review patients' medical records for demographics, fracture morphology, type of surgery and ulnar nerve affection immediately; records were reviewed after surgery and at 2 wk and 12 wk of routine clinical outpatient follow-up. Twenty-nine percent patients were excluded due to pre- or postoperative conditions. Final follow-up examination was a telephone interview in which ulnar nerve affection was reported according to the McGowen Classification Score. A total of 210 patients were eligible for interview, but 13 patients declined participation and 17 patients failed to respond. Thus, 180 patients were included. RESULTS: Mean age at surgery was 64 years (range 18-88 years); 121 (67.3%) patients were women; 59 (32.7%) were men. According to the AO/OTA classification system, we recorded 47 patients with type A3, 55 patients with type B and 78 patients with type C fractures. According to the McGowen Classification Score, mild ulnar nerve affection was reported in nine patients; severe affection, in two. A total of 69 patients were treated with ORIF of whom three had mild temporary ulnar nerve affection and one had severe ulnar nerve affection. In all, 111 patients were treated with arthroplasty (67 EHA, 44 TEA) of whom seven had mild ulnar nerve affection and one had severe persistent ulnar nerve affection. No further treatment was provided. CONCLUSION: The risk of ulnar nerve affection after surgical treatment for acute DHF is low when the ulnar nerve is released in situ without nerve transposition, independently of the treatment provided.

Arthroscopic versus open cancellous bone grafting for scaphoid delayed/nonunion in adults (SCOPE-OUT): study protocol for a randomized clinical trial.

BACKGROUND: Scaphoid non-union results in pain and decreased hand function. Untreated, almost all cases develop degenerative changes. Despite advances in surgical techniques, the treatment is challenging and often results in a long period with a supportive bandage until the union is established. Open, corticocancellous (CC) or cancellous (C) graft reconstruction and internal fixation are often preferred. Arthroscopic assisted reconstruction with C chips and internal fixation provides minimal trauma to the ligament structures, joint capsule, and extrinsic vascularization with similar union rates. Correction of deformity after operative treatment is debated with some studies favouring CC, and others found no difference. No studies have compared time to union and functional outcomes in arthroscopic vs. open C graft reconstruction. We hypothesize that arthroscopic assisted C chips graft reconstruction of scaphoid delayed/non-union provides faster time to union, by at least a mean 3 weeks difference. METHODS: Single site, prospective, observer-blinded randomized controlled trial. Eighty-eight patients aged 18-68 years with scaphoid delayed/non-union will be randomized, 1:1, to either open iliac crest C graft reconstruction or arthroscopic assisted distal radius C chips graft reconstruction. Patients are stratified for smoking habits, proximal pole involvement and displacement of > / < 2 mm. The primary outcome is time to union, measured with repeated CT scans at 2-week intervals from 6 to 16 weeks postoperatively. Secondary outcomes are Quick Disabilities of the Arm, Shoulder and Hand (Q-DASH), visual analogue scale (VAS), donor site morbidity, union rate, restoration of scaphoid deformity, range of motion, key-pinch, grip strength, EQ5D-5L, patient satisfaction, complications and revision surgery. DISCUSSION: The results of this study will contribute to the treatment algorithm of scaphoid delayed/non-union and assist hand surgeons and patients in making treatment decisions. Eventually, improving time to union will benefit patients in earlier return to normal daily activity and reduce society costs by shortening sick leave. TRIAL REGISTRATION: ClinicalTrials.gov NCT05574582. Date first registered: September 30, 2022. Items from the WHO trial registry are found within the protocol.

Short-term survival and patient-reported outcome of total stemless shoulder arthroplasty for osteoarthritis are similar to that of stemmed total shoulder arthroplasty: a study from the Danish Shoulder Arthroplasty Registry.

Background: The use of stemless total shoulder arthroplasty (TSA) for osteoarthritis increases, but there is a paucity on its safety and efficacy and how it performs in comparison with stemmed TSA. The aim was to compare the 5-year cumulative survival rate and patient-reported outcome after stemless and stemmed TSA for osteoarthritis. Methods: We included all stemmed (n = 1197) and stemless (n = 253) TSA for osteoarthritis reported to the Danish shoulder arthroplasty registry from January 1, 2014, to December 31, 2018. Results: Six (2.4%) stemless and 24 (2%) stemmed TSA were revised. The 5-year cumulative implant survival rates were 0.96 for stemless TSA and 0.97 for stemmed TSA. In the multivariate Cox regression model, the hazard ratio for revision was 1.1 (95% confidence interval, 0.5-2.6) for stemless TSA compared with stemmed TSA. The mean Western Ontario Osteoarthritis of the Shoulder (WOOS) index was 82 (standard deviation = 21) for stemmed and 86 (standard deviation = 19) for stemless TSA. The stemless TSA had a statistically significant better WOOS compared with stemmed TSA, but the difference of 6.2 (95% confidence interval, 1.4-10.4) was not regarded as clinically relevant. There was no difference in WOOS between the Nano and the Eclipse systems. Discussion: We found a good 5-year cumulative implant survival rate of stemless TSA, which was comparable with stemmed TSA. Although the stemless TSA had a statistically significant better patient-reported outcome compared with stemmed TSA, the difference was not clinically relevant. Sparing the humeral shaft canal for later revision could be an argument for using stemless TSA instead of stemmed TSA.

Minimal Clinically Important Differences (MCID) for the Western Ontario Osteoarthritis of the Shoulder Index (WOOS) and the Oxford Shoulder Score (OSS).

BACKGROUND: The minimal clinically important difference (MCID) is an important instrument in the interpretation of changes in patient-reported outcome measures (PROM). To our knowledge, no MCID of the Western Ontario Osteoarthritis of the Shoulder Index (WOOS) score has ever been reported and no studies have reported an MCID for the Oxford Shoulder Score (OSS) based on patients with glenohumeral osteoarthritis, treated with an anatomical total shoulder arthroplasty (aTSA). The aim of this study was to determine MCID for WOOS and OSS in a cohort of patients with glenohumeral osteoarthritis treated with an aTSA. METHODS: All patients treated with an aTSA for glenohumeral osteoarthritis at our institution between March 2017 and February 2019 were included. Each patient completed the WOOS and the OSS preoperatively and one year postoperatively. At one year, the patients were asked to rate their overall improvement on a 7-point scale. We used an anchor-based method as our primary method to calculate the MCID, supported by two different distribution-based methods. RESULTS: A total of 45 primary aTSA were included. The MCID of WOOS was 12.3 according to the anchor-based method and 14.2 and 10.3 according to the two distribution-based methods. The MCID of OSS was 4.3 according to the anchor-based method and 5.8 and 4.3 according to the two distribution-based methods. CONCLUSION: The anchor-based method is considered superior to the distribution-based method, and therefore we advocate to use this as MCID. For patients with glenohumeral osteoarthritis treated with an aTSA, the MCID values were 12.3 points for WOOS and 4.3 points for OSS. To our knowledge, this is the first study to report a MCID value for WOOS and the first study to report a MCID value for OSS in this subgroup of patients.

High Completeness and Accurate Reporting of Key Variables Make Data from the Danish Shoulder Arthroplasty Registry a Valuable Source of Information.

PURPOSE: The Danish Shoulder Arthroplasty Registry (DSR) is a nationwide database providing data for research and health care monitoring. The aim of this study was to validate the DSR by (1) assessing registration completeness, (2) comparing key variables with information from medical records, (3) assessing the number and proportion of missing data for key variables. MATERIALS AND METHODS: The completeness of registration in the DSR from 2006-2015 was assessed for primary arthroplasties by comparing the number of arthroplasties reported to the DSR with the number of arthroplasties recorded by the Danish National Patient Register which is an administrative database used by the Danish healthcare authorities to monitor all hospitalizations including shoulder arthroplasty surgery. Positive predictive values (PPV) were used to estimate the accuracy of the reporting in a randomly selected population. Information retrieved from medical records were used as gold standard. The number of missing values for each variable was evaluated to depict if these registrations were missing at random. RESULTS: The completeness of reporting was 94.4. The PPV for the three major indications: osteoarthritis, fracture and rotator cuff arthropathy was 92%, 97%, and 94%, respectively. PPV was high for resurfacing arthroplasty (93%) and reverse shoulder arthroplasty (93%), but low for total shoulder arthroplasty (79%) and hemiarthroplasty (83%). The proportion of missing data in DSR was less than 1% for age, gender, previous surgery, indication and arthroplasty type and these can be regarded as missing at random. CONCLUSION: The study showed that data from the DSR are sufficiently valid to be used for research and quality monitoring. Lower PPV's for total shoulder arthroplasty and hemiarthroplasty are possibly related to inadequate definitions and mutually nonexclusive items in the reporting form. Regular validation is necessary since the data reported to the registry continuously evolve because of changes in clinical practice.

[Osteoarthritis of the shoulder, the elbow and the acromioclavicular joint].

Osteoarthritis of the shoulder is common in elderly, and arthroplasty surgery is increasing in Denmark. This review summarises the current knowledge. Results are good, and revision rates are low at ten years. Symptomatic osteoarthritis in the acromioclavicular joint are common. Most patients can be treated conservatively. Resection arthroplasty complications are rare, and the results are good. Osteoarthritis of the elbow is rare, and only a few arthroplasties are performed. Complications are common, but revision rates are relatively low, and results are improving.

Low arthroplasty survival after treatment for proximal humerus fracture sequelae: 3,245 shoulder replacements from the Nordic Arthroplasty Register Association.

Background and purpose - Proximal humerus fractures (PHF) may result in sequelae indicating arthroplasty. We report cumulative survival rates and reasons for revision after arthroplasty for proximal humerus fracture sequelae (PHFS).Patients and methods - Data were derived from the Nordic Arthroplasty Register Association. The Kaplan-Meier method was used to illustrate survival rates. A scaled Schoenfeld residual plot was used to report the risk of revision for men relative to women in patients who were treated with reverse shoulder arthroplasty (RSA). Revision was defined as removal or exchange of any component or the addition of a glenoid component.Results - 30,190 primary arthroplasties were reported from 2004 to 2016, of which 3,245 were for PHFS. The estimated 1-, 5-, and 10-year cumulative survival rates (95% CI) were 96% (95-97), 90% (89-92), and 86% (83-88) for stemmed hemiarthroplasty and 94% (92-95), 89% (87-91), and 86% (82-90) for RSA with a median time to revision of 18 months (IQR 9-44) and 3 months (IQR 0-17). The risk of revision for men relative to women in patients who were treated with RSA was 3.2 (1.9-5.1) 0-1 year after surgery and 1.9 (0.9-4.1) 1-8 years after surgery. The estimated 1-, 5-, and 10-year cumulative survival rates (95% CI) were 94% (92-96), 88% (85-90), and 80% (75-86) for men and 95% (94-96), 86% (84-89), and 81% (77-84) for young patients.Interpretation - Shoulder arthroplasty for PHFS was associated with lower survival rates, compared with previously published results of shoulder arthroplasty for acute PHF. The low arthroplasty survival rates for men and young patients especially are worrying.

Patients undergoing shoulder arthroplasty for failed nonoperative treatment of proximal humerus fracture have low implant survival and low patient-reported outcomes: 837 cases from the Danish Shoulder Arthroplasty Registry.

Background and purpose - When nonoperative treatment of proximal humerus fracture (PHF) fails, shoulder arthroplasty may be indicated. We investigated risk factors for revision and evaluated patient-reported outcome 1 year after treatment with either stemmed hemiarthroplasty (SHA) or reverse total shoulder arthroplasty (RTSA) after previous nonoperative treatment of PHF sequelae.Patients and methods - Data were derived from the Danish Shoulder Arthroplasty Registry and included 837 shoulder arthroplasties performed for PHF sequelae between 2006 and 2015. Type of arthroplasty, sex, age, and surgery period were investigated as risk factors. The Western Ontario Osteoarthritis of the Shoulder index (WOOS) was used to evaluate patient-reported outcome (0-100, 0 indicates worst outcome). Cox regression and linear regression models were used in the statistical analyses.Results - 644 patients undergoing SHA and 127 patients undergoing RTSA were included. During a mean follow-up of 3.7 years, 48 (7%) SHA and 14 (11%) RTSA were revised. Men undergoing RTSA had a higher revision rate than men undergoing SHA (hazard ratio [HR] 6, 95% confidence interval [CI] 2-19). 454 (62%) patients returned a complete WOOS questionnaire. The mean WOOS score was 53 for SHA and 53 for RTSA. Patients who were 65 years or older had a better WOOS score than younger patients (mean difference 7, CI 1-12). Half of patients had WOOS scores below 50.Interpretation - Shoulder arthroplasty for PHF sequelae was associated with a high risk of revision and a poor patient-reported outcome. Men treated with RTSA had a high risk of revision.

Patient-reported outcome after stemmed versus stemless total shoulder arthroplasty for glenohumeral osteoarthritis: a patient-blinded randomized clinical trial.

BACKGROUND: Stemless shoulder arthroplasty systems with uncemented metaphyseal fixation have been used for glenohumeral osteoarthritis since 2004 (Hawi, et al. BMC Musculoskelet Disord 17:376, 2016). The stemless design has several theoretical advantages compared with the stemmed shoulder arthroplasty systems: restoring patients' anatomy; preserving humeral bone stock; and few complications in component removal if the need for a revision arthroplasty arises. The purpose of the study is to compare the short-term, patient-reported outcome of stemless and stemmed total shoulder arthroplasty (TSA). MATERIALS AND METHODS: A randomized clinical trial will be conducted. Eighty patients with clinical and radiological signs of primary or post-traumatic glenohumeral osteoarthritis, computed tomography (CT) scan-verified adequate glenoid bone stock, and no total rupture of rotator cuff tendons verified by a magnetic resonance imaging (MRI) scan will be randomly allocated to a stemless or stemmed TSA. The primary outcome will be the Western Ontario Osteoarthritis Shoulder (WOOS) score at 12 months. Secondary outcomes are the WOOS score at three months and the Oxford Shoulder Score (OSS) and EQ-5D at 3 and 12 months. All complications, including glenoid and humeral component loosening, instability, rotator cuff tear, intraoperative and postoperative periprosthetic fracture, nerve injury, infection, deltoid injury, and symptomatic deep venous thrombosis, will be reported. DISCUSSION: Findings will provide patients with better information about the potential benefits and harms of stemless and stemmed TSA and will assist shoulder surgeons and patients in decision-making. TRIAL REGISTRATION: Clinicaltrials.gov, NCT03877315 . Registered on 13 March 2019.

High risk for revision after shoulder arthroplasty for failed osteosynthesis of proximal humeral fractures.

Background and purpose - It is unclear whether previous osteosynthesis is a risk factor for inferior outcome following shoulder arthroplasty for a proximal humeral fracture. We used data from the Danish Shoulder Arthroplasty Registry (DSR) to examine this question. Patients and methods - All 285 patients treated with a shoulder arthroplasty after failed osteosynthesis of a proximal humeral fracture reported to DSR from 2006 to 2013 were included. Each case was matched with 2 controls (570) treated with a primary shoulder arthroplasty for an acute proximal humeral fracture. Patient reported outcome was assessed using the Western Ontario Osteoarthritis of the Shoulder index (WOOS) and the relative risk of revision was reported. Results - The mean WOOS was 46 (SD 25) for a shoulder arthroplasty after failed osteosynthesis and 52 (27) after a primary shoulder arthroplasty. The relative risk of revision for a shoulder arthroplasty after failed osteosynthesis was 2 with a primary arthroplasty for fracture as reference. In a separate analysis of patients treated by locking plate the mean WOOS was 46 (24), with a relative risk of revision at 1.5 with a primary arthroplasty as reference. Interpretation - Compared with primary arthroplasty for proximal humeral fracture, we found an inferior patient-reported outcome and a substantial risk of revision for patients treated with a shoulder arthroplasty after failed osteosynthesis for a proximal humeral fracture. The risk and burdens of additional surgery should be accounted for when deciding on the primary surgical procedure.

Long-term clinical results in patients treated for recurrent posterolateral elbow joint instability using an ipsilateral triceps tendon graft.

BACKGROUND: The aim was to report the long-term functional and radiologic outcomes in patients treated for recurrent posterolateral elbow joint instability using an ipsilateral triceps tendon graft. METHODS: We included 18 patients previously treated for posterolateral elbow joint instability and evaluated for clinical results in 2003. Fifteen patients were examined with a mean follow-up period of 19 years (range, 17-22 years). We performed the clinical follow-up with clinical examination of stability, range of motion, pain score on a visual analog scale, Mayo Elbow Performance Score, and Danish version of Oxford Elbow Score. Furthermore, conventional anteroposterior and side-view radiographs of the elbow were obtained to evaluate osteoarthritis, calcifications in the ligaments, and joint subluxation. We evaluated the radiographs by the size of osteophytes, joint space narrowing, and subchondral sclerosis and classified the findings into 3 categories: no osteoarthritis, osteoarthritis, and severe osteoarthritis. RESULTS: All patients had a clinically stable elbow. None had pain while inactive or locking of the joint, and 4 had decreased range of motion. Two patients had a positive pivot-shift stress test, indicating laxity. The mean Mayo Elbow Performance Score was 93 (range, 70-100). The mean Oxford Elbow Score was 45. We observed 5 patients with osteoarthritis and 1 patient with severe osteoarthritis. CONCLUSION: The technique reported by Olsen and Søjbjerg in 2003 gives good long-term results in the treatment of symptomatic posterolateral elbow joint instability, though the development of elbow joint osteoarthritis may decrease the surgical result in the coming years.

Fulminant crural compartment syndrome preceded by psychogenic polydipsia.

We report a case of bilateral anterolateral crural compartment syndrome elicited by hyponatraemia and psychogenic polydipsia. The unusual constellation of clinical findings and diminished pain expression made initial diagnostic procedures challenging. The possible pathogenesis and treatment options are discussed. Impairment of lower extremity function at follow-up was serious and permanent.

Observer bias in randomized clinical trials with time-to-event outcomes: systematic review of trials with both blinded and non-blinded outcome assessors.

BACKGROUND: We wanted to evaluate the impact of nonblinded outcome assessors on estimated treatment effects in time-to-event trials. METHODS: Systematic review of randomized clinical trials with both blinded and nonblinded assessors of the same time-to-event outcome. Two authors agreed on inclusion of trials and outcomes. We compared hazard ratios based on nonblinded and blinded assessments. A ratio of hazard ratios (RHR)<1 indicated that nonblinded assessors generated more optimistic effect estimates. We pooled RHRs with inverse variance random-effects meta-analysis. RESULTS: We included 18 trials. Eleven trials (1969 patients) with subjective outcomes provided hazard ratios, RHR 0.88 (0.69 to 1.12), (I2=44%, P=0.06), but unconditional pooling was problematic because of qualitative heterogeneity. Four atypical cytomegalovirus retinitis trials compared experimental oral administration with control intravenous administration of the same drug, resulting in bias favouring the control intervention, RHR 1.33 (0.98 to 1.82). Seven trials of cytomegalovirus retinitis, tibial fracture and multiple sclerosis compared experimental interventions with standard control interventions, e.g. placebo, no-treatment or active control, resulting in bias favouring the experimental intervention, RHR 0.73 (0.57 to 0.93), indicating an average exaggeration of nonblinded hazard ratios by 27% (7% to 43%). CONCLUSIONS: Lack of blinded outcome assessors in randomized trials with subjective time-to-event outcomes causes high risk of observer bias. Nonblinded outcome assessors typically favour the experimental intervention, exaggerating the hazard ratio by an average of approximately 27%; but in special situations, nonblinded outcome assessors favour control interventions, inducing a comparable degree of observer bias in the reversed direction.

Benefits and harms of locking plate osteosynthesis in intraarticular (OTA Type C) fractures of the proximal humerus: a systematic review.

INTRODUCTION: Locking plate osteosynthesis of proximal humeral fractures are widely recommended and used, even in complex intraarticular fracture patterns such as AO/OTA Type C fractures. We systematically reviewed clinical studies assessing the benefits and harms of osteosynthesis with angle stable plates in AO/OTA Type C fractures of the proximal humerus. METHODS: We conducted an iterative search in PubMed, Embase, Cochrane Library, Web of Science, Cinahl, and PEDro in all languages from 1999 to November 2010. Eligible studies should study the outcome for Type C fractures after primary osteosynthesis with locking plate within two weeks of injury, and a follow-up period of six months or more. Patients should be evaluated with the Constant-Murley Score (CS). Two observers extracted data independently. RESULTS: Twelve studies and 282 Type C fractures were included. Results were categorised according to study type and synthesised qualitatively. No randomised clinical trials were identified. Two comparative, observational studies reported a mean CS of 71 (relative to contralateral shoulder) and 75 (non-adjusted Constant Score) for Type C fractures. For all studies mean non-adjusted CS ranged from 53 to 75. Mean age- and sex-adjusted CS ranged from 60 to 88. Mean CS relative to the contralateral shoulder ranged from 71 to 85. The most common complications were avascular necrosis (range, 4-33%), screw perforations (range, 5-20%), loss of fixation (range, 3-16%), impingement (range, 7-11%) and infections range 4-19%. Reoperation rate ranged from 6 to 44%. CONCLUSIONS: Insufficient study designs and unclear reporting preclude safe treatment recommendations. Complication and reoperation rates were unexpected high. Based on the studies included we cannot routinely recommend the use of locking plates in AO/OTA Type C fractures.