J.-F. Kempf

Pitfalls and complications with locking plate for proximal humerus fracture

PURPOSEnThe aim of this study was to identify specific complications of locking plate fixation of proximal humerus fractures.nnnPATIENTS AND METHODSnSeventy-three adult patients with a displaced 3- (24%) or 4-part (76%) fracture of the proximal humerus were treated over a period of 2 years under the supervision of a trauma surgeon. Fourty-four patients came back for a clinical and radiographic examinations at least 18 months after the trauma; the others were evaluated at 6 weeks and 3 and 6 months.nnnRESULTSnOut of the 73 patients (64.4% females, mean age of 65), 11 patients needed a second surgery and 18 were lost for follow-up after 6 months. Mean final constant score was 62.3 points. The incidence of secondary displacement was 8.2%. Nonunion rate was 5.5%, affecting the constant score (P = .018). 16.4% of the patients developed a partial necrosis of the humeral head at the latest follow-up, which influenced on the constant score (P = .029). Quality of the reduction of the greater tuberosity influenced final results (P = .037). Screw cutout rate was 13.7%, with an influence to the constant score (P = .001). A too high plate positioning influenced the constant score (P = .002).nnnCONCLUSIONnLocked screw-plates provide more secure fixation of fractures, especially in weak bone. Complications rate remains high. Two complications are to be distinguished: 1) technical complications in plate positioning, length of the screws or secondary screw cutout strongly influence the final clinical result; and 2) specific complications related to this technology such as pseudarthrosis or plate fracture.

Effects of freezing/thawing on the biomechanical properties of human tendons.

Abstract Numerous biomechanical studies using osteoarticular complex need frozen cadaveric specimens. Some of these studies deal with the resistance of the tendinous structures, for example the resistance of some autografts, such as the patellar ligament and the semitendinosus and gracilis tendons for reconstruction of the anterior cruciate ligament. The aim of this study was the in-vitro evaluation of the mechanical modifications induced by freezing/thawing on human tendons. The long head of the biceps brachii tendon was used as the reference. Eight pairs of tendons of the long head of the biceps brachii were taken from eight fresh cadavers. After drawing lots, one was tested immediately, the other was deep-frozen and then thawed. With an Instron material-testing machine, we performed a relaxation test and a uniaxial tensile test, to estimate the ultimate tensile failure and the elastic modulus of each pair of tendons. Freezing had no influence on the tendinous relaxation, but altered significantly the ultimate tensile failure and Young’s modulus of the tendons.

Recurrence after arthroscopic Bankart repair: Is quantitative radiological analysis of bone loss of any predictive value?

INTRODUCTIONnBone defects in the humeral head or antero-inferior edge of the glenoid cavity increase recurrence risk following arthroscopic Bankart repair. The present study sought to quantify such preoperative defects using a simple radiological technique and to determine a threshold for elevated risk of recurrence.nnnMATERIALS AND METHODSnA retrospective study conducted in two centers enrolled patients undergoing primary arthroscopic Bankart repair for isolated anterior shoulder instability in 2005. The principle assessment criterion was revision for recurrent instability. Quantitative radiology comprised: the ratio of notch depth to humeral head radius (D/R) on AP view in internal rotation; Gerbers X ratio between antero-inferior glenoid cavity edge defect length and maximum anteroposterior glenoid cavity diameter on arthro-CT scan; and the D1/D2 ratio between the glenoid joint surface diameters of the pathologic (D1) and healthy (D2) shoulders on Bernageau glenoid profile views. Seventy-seven patients were included, with a mean follow-up of 44 months (range, 36-54).nnnRESULTSnOverall recurrence rate was 15.6%. Recurrence risk was significantly greater when the humeral notch length was more or equal to 20% of the humeral head diameter and the Gerber ratio more or equal to 40%. On Bernageau views, mean D1/D2 ratio was 4.2% (range, 0-23%) in patients without recurrence, versus 5.1% (range, 0-19) in those with recurrence (P=0.003).nnnDISCUSSIONnBeyond the above thresholds, bone defect as such contraindicates isolated arthroscopic stabilization. The D/R and Gerber ratios are simple and reproducible quantitative measurements can be taken in routine practice, enabling preoperative planning of complementary bone surgery as needed.nnnLEVEL OF EVIDENCEnLevel IV; retrospective cohort study.

Relationships of the musculocutaneous nerve and the coracobrachialis during coracoid abutment procedure (Latarjet procedure)

PurposeThe aim of this study was first to define first the anatomical relationships between the musculocutaneous nerve and the coracobrachialis, and then the induced modifications of these relationships by a preglenoid transposition of the vertical part of the coracoid process.Materials and methodsTwenty-one embalmed adult trunks and upper limb were dissected. First the coracobrachialis and the musculocutaneous nerve were identified through a deltopectoral approach. We measured the distances between the lateral cord of the brachial plexus and the entry point of the nerve, between the inferior tip of the tip of the coracoid process and the penetration of the nerve or its twigs, and finally the angle between the general axis of the coracobrachialis and the axis of the musculocutaneous nerve. The same measures were performed after the coracoid bone block abutment.ResultsProximal motor branches destined to the coracobrachialis varied from 0 to 3. Mean distance between the lateral cord of the brachial plexus and entry point of the nerve into the muscle was 47.2xa0mm before and 48.43xa0mm after the coracoid transfer. Mean angulations between the nerve and the muscle was 121° before and 136° after the transfer of the coracoid process. Mean distance between the inferior tip of the coracoid process and entry point of the nerve into the muscle was 55.7xa0mm, reduced to 48.6xa0mm after the coracoid transposition. Finally, the distance between the tip of the coracoid and the first motor twig entering the coracobrachialis was less than 50xa0mm in 75% of the cases with a mean value of 40.6xa0mm.ConclusionsLesion of the musculocutaneous nerve is a known complication of the coracoid bone block abutment procedure (Latarjet–Bristow). From this study we know that they are due to lengthening of the nerve and modification of the penetration angle of the nerve into the coracobrachialis. We also infer that some motor nerve destined to the coracobrachialis might be damaged during the proximal medial release of the muscle after the detachment of the pectoralis minor muscle.

Morphological analysis of the glenoid version in the axial plane according to age

PurposeTotal shoulder arthroplasty planning requires a preoperative assessment of the glenoid version. This study aimed to determine the morphologic profile of the glenoid cavity and our null hypothesis was that age may affect the spiraling aspect.Method114 CT arthrographies of patients from 15 to 78xa0years old were included. Four groups were defined according to age: 15–29, 30–44, 45–59xa0years old, and over 60. The version of the glenoid was measured in the axial plane according to the most common method: a line is drawn between the osseous anterior and posterior margins of the glenoid and the version corresponds to the angle between this line and the transverse axis of the glenoid. The transverse axis of the scapula is determined by a line drawn from the center of the glenoid fossa to the medial border of the scapula. The axial plane (perpendicular to the supero-inferior axis of the glenoid cavity) was defined by multiplanar reconstruction. The measurements were performed at three regions of interest: the level of the coracoid process (region A), the level of the notch on the anterior border of the glenoid (region B), and the region of the greater antero-posterior diameter (region C).Results96xa0% of the glenoid cavities included were retroverted. The mean version in region A was 11.9° (0–24.3, S-D 5.2), in region B 6.85° (−5.2 to 12.1, S-D 4.13) and in region C 4.04° (−7.7 to 11.1, S-D 4.04). The difference between the mean version of region A and region B was 5.02° and the difference between the mean version of the region B and the mean version of the region C was 2.81°. When considering the rate of change of the mean version between two adjacent regions, no difference was observed between the four groups of age.DiscussionThe analysis showed the importance of the axial reconstruction plan chosen to allow interpretable and reproducible measures. A decreasing version of the glenoid superior-to-inferior was observed, presenting a spiraling twist as described in previous studies. The profile of variation does not change in the four groups of patients included. The reconstruction of an articular surface as close to the anatomy as possible would also participate in establishing the muscular balance and the constraints on implants. Up to now, implants do not take into account this cranio-caudal twisting.

Biomechanics of open Bankart and coracoid abutment procedures in a human cadaveric shoulder model.

The specific aims of this experiment were (1) to develop a clinically relevant model of anteroinferior shoulder dislocation in the apprehension position to compare the biomechanics of the intact anterior capsuloligamentous structures, and (2) to evaluate the initial strength of an open Bankart and of a coracoid abutment procedure. Fifteen shoulders from deceased donors were used. For the intact shoulders, mean peak load was 486 N, and stiffness was 26,7 N/mm. For the Bankart repair, the mean peak load was 264 N, and mean stiffness was 14.1 N/mm. Transosseous repairs failed by suture pullout through soft tissues. For the coracoid abutment repair, the mean peak load was 607 N and stiffness was 25.57 N/mm. This study reveals that the biomechanical performance of the Bankart and coracoid abutment repairs fails to reproduce the properties of the natural intact state.

Revisions of total shoulder arthroplasty: Clinical results and complications of various modalities

INTRODUCTIONnThe number of primary total shoulder arthroplasties has increased exponentially in recent years, with a corresponding increase in the number of revision procedures.nnnOBJECTIVEnTo assess clinical results and complications in a series of shoulder implant replacement, of whatever etiology.nnnMATERIALS AND METHODSnThirty-seven patients, with a mean age of 68.3±11.8xa0years at time of implant replacement, were included in a retrospective study. Mean interval between primary arthroplasty and revision was 78.4±59.7xa0months (range, 1-200xa0months). The main assessment criterion was changed in Constant score between preoperative value and follow-up. Secondary criteria were: onset of intra- and postoperative complications, and reoperation related to a complication.nnnRESULTSnMean follow-up was 41.5±32.0xa0months (range, 12-105xa0months). Absolute Constant score increased by a mean 17.5±15.1xa0points (P<0.001) and weighted Constant score by 26.3±23.6xa0points (P<0.001). Intraoperative complications occurred in 24.3% of patients (9/37) and postoperative complications in 29.7% (11/37). Among the patients, 21.6% (8/37) required reoperation for postoperative complications. Overall, 54% of patients (20/37) suffered from intra- or postoperative complications.nnnCONCLUSIONnShoulder implant replacement improved function in the present series, but with a high rate of complications and reoperations.nnnLEVEL OF EVIDENCEnIV, retrospective case-control study without control group.

The intra- and inter-observer reliability of the CT-scan based X index to quantify glenoid bone loss in chronic anterior shoulder instability and its impact on decision making

PurposeThe X index is a measure of the antero-inferior glenoid bone loss on unilateral 2D CT-scans in the preoperative analysis of chronic anterior shoulder instability. Recurrence rate was shown to be higher after stabilization surgery if X index is superior or equal to 0.4. The objective of this study was to assess the intra- and inter-observer reliability of the X index.MethodsSixty patients with an X indexxa0≥0.4 were included retrospectively. The X index was measured twice by two independent evaluators, 15xa0days apart. The measurement was performed on a unilateral 2D CT-scan by dividing the length of the antero-inferior glenoid defect over the maximal antero-posterior diameter of the glenoid. Reliability of X index was assessed with intra-class correlation coefficient (ICC, ρ). Two points were added to the ISIS calculation if its glenoid criterion was “zero” and we compared this modified score to the original one.ResultsThe intra-observer reliability of the X index measurement was “excellent” (ρxa0=xa00.95xa0±xa00.01, pxa0<xa00.0001) while the inter-observer reliability was “good” (ρxa0=xa00.59xa0±xa00.08, pxa0<xa00.0001). In patients with a glenoid bone loss visualized by the X index, 48.3xa0% had a negative sclerotic glenoid line sign. This proportion significantly decreased with the augmentation of the X index, pxa0=xa00.02. The average original ISIS score was 3.4xa0±xa01.9 and became 4.3xa0±xa01.7 (pxa0<xa00.00001) when the X index was incorporated.ConclusionsThe X index is a reliable and simple unilateral 2D CT-scan measurement. AP shoulder radiographs significantly underestimated glenoid bony lesions.

Osteoarthritis after rotator cuff repair: A 10-year follow-up study

BACKGROUNDnJoint surgery is often complicated by gradual bone and cartilage deterioration that eventually leads to secondary osteoarthritis. The primary objective of this study was to identify preoperative risk factors for gleno-humeral osteoarthritis after rotator cuff repair. The secondary objectives were to assess whether the risk of gleno-humeral osteoarthritis was influenced by the operative technique, occurrence of postoperative complications, cuff healing, and muscle degeneration and to determine whether gleno-humeral osteoarthritis affected the clinical outcome.nnnHYPOTHESISnThe development of gleno-humeral osteoarthritis affects the postoperative clinical outcome.nnnMATERIAL AND METHODnA retrospective multicentre study of patients who underwent rotator cuff repair in 2003 and were re-evaluated at least 10xa0years later was conducted under the aegis of the Société française de chirurgie orthopédique et traumatique (SOFCOT). Osteoarthritis severity was graded according to the Samilson-Prieto classification.nnnRESULTSnFour hundred and one patients were included. At last follow-up, at least 10xa0years after surgery, the radiological Samilson-Prieto grades were distributed as follows: 0, n=181 (45%); 1, n=142 (n=35%); 2, n=57 (14%); 3, n=14 (4%); and 4, n=7 (2%). The mean Constant score was significantly higher in the patients without than with osteoarthritis at last follow-up (79/100 vs. 73/100, P<0.001). MRI assessment of cuff healing showed that the proportion of patients with osteoarthritis was significantly higher in the group with unhealed or re-torn cuffs (Sugaya typexa04 or 5) than in the group with healed cuffs (Sugaya typexa01, 2, or 3) (46% vs. 25%, P=0.012).nnnDISCUSSIONnOur study showed no associations linking the risk of gleno-humeral osteoarthritis to the patient activity profile, history of shoulder injury, or preoperative symptom duration. In contrast, statistically significant associations were identified between gleno-humeral osteoarthritis and age, male gender, initial tear severity, and the pain and mobility components of the preoperative Constant score. Decreased invasiveness of the operative technique probably diminishes the long-term risk of osteoarthritis. An unhealed or re-torn cuff increases the risk of osteoarthritis. Osteoarthritis is associated with poorer final clinical outcomes.nnnLEVEL OF EVIDENCEnIV, retrospective non-randomised study.

Intra- and inter-observer agreement in MRI assessment of rotator cuff healing using the Sugaya classification 10 years after surgery

BACKGROUNDnThe long-term outcomes of rotator cuff repair are unclear. Recurrent tears are common, although their reported frequency varies depending on the type and interpretation challenges of the imaging method used. The primary objective of this study was to assess the intra- and inter-observer reproducibility of the MRI assessment of rotator cuff repair using the Sugaya classification 10years after surgery. The secondary objective was to determine whether poor reproducibility, if found, could be improved by using a simplified yet clinically relevant classification.nnnHYPOTHESISnOur hypothesis was that reproducibility was limited but could be improved by simplifying the classification.nnnMATERIAL AND METHODnIn a retrospective study, we assessed intra- and inter-observer agreement in interpreting 49 magnetic resonance imaging (MRI) scans performed 10years after rotator cuff repair. These 49 scans were taken at random among 609 cases that underwent re-evaluation, with imaging, for the 2015 SoFCOT symposium on 10-year and 20-year clinical and anatomical outcomes of rotator cuff repair for full-thickness tears. Each of three observers read each of the 49 scans on two separate occasions. At each reading, they assessed the supra-spinatus tendon according to the Sugaya classification in five types.nnnRESULTSnIntra-observer agreement for the Sugaya type was substantial (κ=0.64) but inter-observer agreement was only fair (κ=0.39). Agreement improved when the five Sugaya types were collapsed into two categories (1-2-3 and 4-5) (intra-observer κ=0.74 and inter-observer κ=0.68).nnnCONCLUSIONnUsing the Sugaya classification to assess post-operative rotator cuff healing was associated with substantial intra-observer and fair inter-observer agreement. A simpler classification into two categories improved agreement while remaining clinically relevant.nnnLEVEL OF EVIDENCEnII, prospective randomised low-power study.