Dual plate constructs have become an increasingly common fixation technique for midshaft clavicle fractures and typically involve the use of mini-fragment plates. The goal of this technique is to reduce plate prominence and implant irritation, as these are common reasons for revision surgery. However, limited biomechanical data exist for these lower-profile constructs. The study aim was to compare dual mini-fragment orthogonal plating to traditional small-fragment clavicle plates for biomechanical non-inferiority and to determine if an optimal plate configuration could be identified, using a cadaveric model.

Twenty-four cadaveric clavicles were randomized to one of six groups (n=4 per group), stratified by CT-based bone mineral content (BMC). The six different plating configurations compared were: pre-contoured superior or anterior fixation using a single 3.5-mm LC-DC plate, and four different dual-plating constructs utilizing 2.4-mm and 2.7-mm reconstruction or LC-DC plates. The clavicles were plated and then osteotomized to create an inferior butterfly fracture, which was then fixed with a single interfragmentary screw (OTA 15.2B). Axial, torsional, and bending (anterior and superior surface loading) stiffness were determined for each construct through non-destructive cyclic testing, using an MTS 858 Bionix materials testing system. This was followed by a load-to-failure test in three-point superior-surface bending. Kruskal-Wallace H and Mann-Whitney U were used to test for statistical significance.

There were no significant differences in BMC (median 7.9 g, range 4.2-13.8 g) for the six groups (p=1.000). For axial stiffness, the two dual-plate constructs with a superior 2.4-mm and anterior 2.7-mm plate (either reconstruction or LC-DC) were significantly stiffer than the other four constructs (p=0.021). For both superior and anterior bending, the superior 2.4-mm and anterior 2.7-mm plate constructs were significantly stiffer when compared to the 3.5-mm superior plate (p=0.043). In addition, a 3.5-mm plate placed anterior was a stiffer construct than a superior 3.5-mm plate (p=0.043). No significant differences were found in torsional stiffness or load-to-failure between the different constructs.

Dual plating using mini-fragment plates is biomechanically superior for fixation of midshaft clavicle fractures when compared to a single superior 3.5-mm plate and has similar biomechanical properties to a 3.5-mm plate placed anteriorly. With the exception of axial stiffness, no significant differences were found when different dual plating constructs were compared to each other. However, placing a 2.4-mm plate superiorly in combination with a 2.7-mm plate anteriorly might be the optimal construct, given the biomechanical superiority over the 3.5-mm plate placed superior.

Nearly one quarter of ankle fractures have a recognized syndesmosis injury. An intact syndesmosis ligament complex stabilizes the distal tibio-fibular joint while allowing small, physiologic amounts of relative motion. When injured, malreduction of the syndesmosis has been found to be the most important independent factor that contributes to inferior functional outcomes. Despite this, significant variability in surgical treatment remains. This may be due to a poor understanding of normal dynamic syndesmosis motion and the resultant impact of static and dynamic fixation on post-injury syndesmosis kinematics. As the syndesmosis is a dynamic structure, conventional CT static images do not provide a complete picture of syndesmosis position, giving potentially misleading results. Dynamic CT technology has the ability to image joints in real time, as they are moved through a range-of-motion (ROM). The aim of this study was to determine if syndesmosis position changes significantly throughout ankle range of motion, thus warranting further investigation with dynamic CT.

This is an a priori planned subgroup analysis of a larger multicentre randomized clinical trial, in which patients with AO-OTA 44-C injuries were randomized to either Tightrope or screw fixation. Bilateral ankle CT scans were performed at 1 year post-injury, while patients moved from maximal dorsiflexion (DF) to maximal plantar flexion (PF). In the uninjured ankles, three measurements were taken at one cm proximal to the ankle joint line in maximal DF and maximal PF: Anterior (ASD), middle (MSD), and posterior (PSD) syndesmosis distance, in order to determine normal syndesmosis position. Paired samples t-tests compared measurements taken at maximal DF and maximal PF.

Twelve patients (eight male, six female) were included, with a mean age of 44 years (±13years). The mean maximal DF achieved was 1-degree (± 7-degrees), whereas the mean maximal PF was 47-degrees (± 8-degrees). The ASD in DF was 3.0mm (± 1.1mm) versus 1.9mm (± 0.8mm) in PF (p<0.01). The MSD in DF was 3.3mm (±1.1mm) versus 2.3mm (±0.9mm) in PF (p<0.01). The PSD in DF was 5.3mm (±1.5mm) versus 4.6mm (±1.9mm) in PF (p<0.01). These values are consistent with the range of normal parameters previously reported in the literature, however this is the first study to report the ankle position at which these measurements are acquired and that there is a significant change in syndesmosis measurements based on ankle position.

Normal syndesmosis position changes in uninjured ankles significantly throughout range of motion. This motion may contribute to the variation in normal anatomy previously reported and controversies surrounding quantifying anatomic reduction after injury, as the ankle position is not routinely standardized, but rather static measurements are taken at patient-selected ankle positions. Dynamic CT is a promising modality to quantify normal ankle kinematics, in order to better understand normal syndesmosis motion. This information will help optimize assessment of reduction methods and potentially improve patient outcomes. Future directions include side-to-side comparison using dynamic CT analysis in healthy volunteers.

The long head of the biceps tendon has been proposed as a source of pain in patients with rotator cuff tears. The purpose of this study is to evaluate the objective, subjective, and radiographic results of arthroscopic biceps tenotomy in selected patients with rotator cuff tears. Three hundred seven arthroscopic biceps tenotomies were performed in patients with full thickness rotator cuff tears. All patients had previously failed appropriate nonoperative management. Patients were selected for arthroscopic tenotomy if the tear was thought to be irreparable or the patient was older and not willing to participate in the rehabilitation required following rotator cuff repair. One hundred eleven shoulders underwent a concomitant acromioplasty. The mean age at surgery was 64.3 years. The mean preoperative radiographic acromiohumeral interval measured 6.6 mm. Patients were evaluated clinically and radiographically at a mean 57 months follow-up (range 24 to 168 months). The mean Constant score increased from 48.4 points preoperatively to 67.6 points postoperatively (p < 0.0001). Eighty-seven percent of patients were satisfied or very satisfied with the result. Nine patients underwent an additional surgical procedure (three for attempt at rotator cuff repair and six for reverse prostheses for cuff tear arthropathy). The acromiohumeral interval decreased by a mean

1.3 mm during the follow-up period and was associated with longer duration of follow-up (p < 0.0001). Preoperatively, 38% of patients had glenohumeral arthritis; postoperatively, 67% of patients had glenohumeral arthritis. Concomitant acromioplasty was statistically associated with better subjective and objective results only in patients with an acromiohumeral distance greater than 6 mm. Fatty infiltration of the rotator cuff musculature had a negative influence on both the functional and radiographic results (p < 0.0001). Arthroscopic biceps tenotomy in the treatment of rotator cuff tears in selected patients yields good objective improvement and a high degree of patient satisfaction. Despite these improvements, arthroscopic tenotomy does not appear to alter the progressive radiographic changes that occur with long standing rotator cuff tears.

Background: Rotator cuff tears involving the subscapularis are less common than those involving the posterior superior rotator cuff. The purpose of this study is to report the results of repair of isolated tears of the subscapularis.

Methods: Eighty-four shoulders that had undergone open repair of the subscapularis tendon were reviewed. The mean age at surgery was 53.2 years. The mean interval from onset of symptoms to surgery was 12.5 months. Fifty-seven tears were traumatic, and twenty-seven were degenerative in etiology. Twenty-three of the tears involved the superior third of the subscapularis tendon, forty-one involved the superior two thirds, and twenty were complete tears. Fifty-four shoulders had a dislocation or subluxation of the long head of the biceps tendon, while ten shoulders had a rupture of the long head of the biceps tendon. Forty-eight shoulders underwent concomitant biceps tenodesis; thirteen shoulders underwent concomitant biceps tenotomy; and four shoulders underwent concomitant recentering of the biceps. Patients were evaluated clinically and radiographically at a mean fortyfive month follow-up (range 24 to 132 months).

Results: The mean Constant score increased from 55.0 points preoperatively to 79.5 points postoperatively (p< 0.001). Seventy-five patients were satisfied or very satisfied with the result. Preoperatively, four patients had mild glenohumeral arthritis. Postoperatively, twenty-five patients had mild glenohumeral arthritis and two patients had moderate glenohumeral arthritis. Tenodesis or tenotomy of the biceps tendon at the time of subscapularis repair was associated with improved subjective and objective results independent of the preoperative condition of the biceps tendon.

INTRODUCTION: Assessment of radiolucent lines (RLL) is the main component of the radiographic analysis of the glenoid component. The purpose of this study is to compare the radiographic results of two glenoid preparation techniques by analyzing periglenoid radiolucencies.

MATERIEL AND METHODS: The series consists of seventy-two shoulder arthroplasties with primary osteoarthritis. Shoulders were divided into two groups based on glenoid preparation technique:

Group 1: Thirty-seven shoulders operated on between 1991 and 1995 with flat back, polyethylene glenoid implants cemented after “curettage” of the keel slot.

Group 2: Thirty-five shoulders operated on between 1997 and 1999 with flat back, polyethylene glenoid implants cemented after cancellous bone compaction of the keel slot.

At least three of the following four fluoroscopically positioned, postoperative AP radiographs were analyzed: immediate postoperative, between the 3rd and 6th postoperative months, at one year postoperative and at two years postoperative. The immediate and the two year radiograph were required for study inclusion. The radiolucent line score (RLLS) was calculated using the technique of Molé, involving the summation of radiolucencies in each of six specified zones. The RLLS was compared between the two groups.

RESULTS: On the immediate postoperative radiographs the average of the total RLL score of the 9 analyzes was 2.39 in Group 1 and 1.67 in Group 2 (p=0.042). There was a statistically significant association between the glenoid preparation technique and the incidence of radiolucency around the keel as well (p=0.001). There was no significant difference in radiolucency behind the faceplate between the two groups (Group 1: 1.54 and Group 2: 1.41; p=0.394). On the 2-year postoperative radiographs the average RLL score of the 9 analyzes were 6.44 in the Group1 (4.05 under the tray, and 2.39 around the keel), and 4.19 in Group2 (p=0.0005) (2.86 under the tray, and 1.33 around the keel). The radiolucency around the keel and behind the faceplate (p=0.0005) was significantly more important (p=0.001) in the “curettage” glenoid preparation population. A significantly higher degree of progression of the total RLL score (p=0.002) and of the radiolucency behind the faceplate (p=0.001) was observed in the “curettage” glenoid preparation group.

DISCUSSION/CONCLUSION: Preparation of the glenoid component keel slot with cancellous bone compaction is radiographically superior to the “curettage” technique with regard to periglenoid radiolucen-cies. Although new techniques of glenoid preparation may help to decrease the rate of RLL, this study shows that even with better technique, the RLL are evolutive and may appear after few years in initially perfectly implanted glenoid.

Purpose: The glenoid and humeral head curvature radii are mismatched in non-constrained total shoulder prostheses. The purpose of this study was to evaluate the effect of this mismatch on radiographic lucent lines and clinical outcome.

Material and methods: The study population included 319 total shoulder prostheses issuing from a multicentric European cohort. The patients underwent surgery for primary shoulder degeneration. Mean age at surgery was 67 years. Female sex predominated (75%). Partial supraspinatous tears were present in 7% of the shoulders with full-thickness tears also in 7%. A single type of prosthesis was used composed of a humeral pivot with a modular head (seven head sizes) and a cemented polyethylene flat-surface spiked glenoid (three sizes). Variable association of humeral heads and prosthetic glenoids defined the mismatch which varied from 0 to 10 mm (difference in the curvature radii between the head and glenoid). The patients were reviewed clinically and radiologically at a mean follow-up of 53.5 months (24–110 months). Clinical outcome was assessed with the Constant score for pain (15 points), daily activity (20 points), motion (40 points), and force (25 points). The glenoid lucent line was evaluated on the AP view using a 0 to 18 point scale (0=absence, 18=lucent line in 6 zones). Analysis of variance and linear regression were used to assess the effect of mismatch on the glenoid lucent line and clinical outcome.

Results: There was a statistically significant linear relationship between mismatch and glenoid lucent lines. The lucent line score was significantly lower when the mismatch was between 6 and 10mm. Mismatch had no influence on the overall Constant score or the individual scores (pain, motion, force, daily activities) nor on early or late postoperative complications.

Discussion: Based on the results of this study, the first in vivo assessment, the “ideal” gleno-humeral mismatch for total shoulder prostheses would be between 6 and 10 mm, i.e. much greater than is classically recommended (0–5 mm).

Purpose: Centred degeneration of the shoulder joint is defined as a degeneration of the glenohumeral surfaces without ascension of the humeral head. We investigated the influence of partial or full thickness rotator cuff tears and/or fatty degeneration of the supraspinatus on the results of total shoulder arthroplasty.

Material and methods: During a multicentric review of 766 cases of centred degeneration of the shoulder joint treated with the Aequalis prosthesis, we identified 555 shoulders in 478 patients with an interpretable preoperative arthroscan. All patients were reviewed with a minimum follow-up of two years (mean 3.6 years). Constant score and radiological findings were recorded. We identified 41 shoulders with partial tears of the supraspinatus and 42 shoulders with full-thickness tears of the supraspinatus alone. Moderate fatty degeneration was observed in 90 shoulders (≤ 2) and severe fatty degeneration of the infraspinatus or the subscapularis (> 2) in 15. We analysed the Constant scores, subjective results, radiological results, and rate of complications in each of these populations.

Results: Rotator cuff tears involving the supraspinatus alone did not have a destabilising effect, the head of the humerus did not influence the postoperative result assessed by the overall Constant score, motion in all planes, subjective result, radiological result, or rate of complications. There was no significant difference in complication rate. Presence or not of cuff repair did not influence these results. Inversely, fatty degeneration ≥ 2 involving the infrastpinatus or the subscapularis had a significant effect, decreasing the Constant score, active external rotation, active anterior elevation, and subjective result. On the contrary, it did not influence the radiological results or the rate of complications.

Discusssion: This multicentric study confirms that the degenerated shoulder joint can remain centred with a solitary tear of the supraspinatus. This has no effect on the clinical result and does not require repair. Inversely, fatty degeneration is highly predictive of the quality of the final result.

Purpose: The best strategy to adopt for the long head of the biceps during total shoulder arthroplasty for centred primary joint degeneration remains a controversial issue. We analysed the influence of long head of the biceps (LHB) tenodesis on outcome.

Material and methods: From retrospective multicentric series of 766 shoulder prostheses implanted for centred primary degeneration of the shoulder joint, we selected 625 shoulders with sufficient data concerning the LHB. We defined two groups: 131 shoulders with LHB tenodesis and 494 shoulders with a preserved LHB. We analysed clinical outcome with the Constant score and subjective outcome at two years. We identified four groups: 70 humeral prostheses without tenodesis, 10 humeral prostheses with tenodesis, 424 total shoulder arthroplastues without tenodesis, and 121 total shoulder arthroplasties with tenodesis.

Results: The Constant score was significantly better in the tenodesis group (74.7) than in the group without tenodesis (70.8). This significant difference was also found for the weighted score and likewise for active anterior elevation and active external rotation in position 1. There was no difference concerning postoperative fatty degeneration. By subgroups, the analysis showed significant improvement in the Constant score for humeral prostheses with tenodesis and total shoulder arthroplasty with tenodesis over the same implants without tenodesis. This same significant difference was observed for the 364 patients who had a minimum follow-up of 36 months: tenodesis improved the Constant score, the weighted Constant score, active anterior elevation, and active external rotation.

Discussion: The causal role of the LHB in shoulder pain is now well documented in the literature. Several authors have advocated tenotomy or tenodesis of the LHB during surgical treatment of rotator cuff tears. The same is not true for shoulder arthroplasty for the treatment of primary degeneration. Dines and Hersch reported their experience with ten patients with a painful total shoulder arthroplasty who were improved with arthroscopic tenotomy or tenodesis.

Conclusion: Our large series confirms that tenodesis of the LHB is preferable during implantation of a humeral prosthesis or a total shoulder prosthesis for the treatment of centred primary joint degeneration with good results that persist over time.