Double-Screw Osteosynthesis in an Unstable Scaphoid Fracture Model: A Biomechanical Comparison of Two Screw Configurations.

PURPOSE: Although there is evidence that a single headless compression screw is sufficient for fixation of most scaphoid fractures, double-screw osteosynthesis has been shown to result in higher failure strength and stiffness than a single screw. However, the biomechanical effect of different screw configurations has not been determined. METHODS: A standardized unstable fracture model was produced in 28 cadaveric scaphoids. Specimens were randomly allocated to 1 of 2 fixation groups using 2 internal compression screws positioned in either the sagittal or coronal plane. A specimen-specific 3-dimensionally-printed customized screw placement and osteotomy device was developed using computer-aided design-generated models derived from computed tomography scan data of each individual scaphoid. Load to failure and stiffness of the repair constructs were evaluated using a mechanical testing system. RESULTS: There were no significant differences in size, weight, and density between the scaphoid specimens. The average distance between screws was significantly greater in the sagittal group than in the coronal group. There were no significant differences between the coronal and sagittal aligned double screws in load to 2 mm displacement (mean coronal 180.9 ± 109.7 N; mean sagittal 156.0 ± 85.8 N), load to failure (mean coronal 275.9 ± 150.6 N; mean sagittal 248.0 ± 109.5 N), stiffness (mean coronal 111.7 ± 67.3 N/mm; mean sagittal 101.2 ± 45.1 N/mm), and energy absorption (mean coronal 472.6 ± 261.4 mJ; mean sagittal 443.5 ± 272.7 mJ). CONCLUSIONS: There are no significant biomechanical differences between the sagittal or coronal aligned double headless compression screws in a scaphoid fracture model with bone loss. CLINICAL RELEVANCE: In cases where double-screw fixation of the scaphoid is being considered, the placement of double screws can be at the discretion of the surgeon, and can be dictated by ease of access, surgical preference, and fracture orientation.

Measurement of Scaphoid Bone Microarchitecture: A Computed Tomography Imaging Study and Implications for Screw Placement.

PURPOSE: High bone density and quality is associated with improved screw fixation in fracture fixation. The objective of this study was to assess bone density and quality in the proximal and distal scaphoid to determine optimum sites for placement of 2 screws in scaphoid fracture fixation. METHODS: Twenty-nine cadaveric human scaphoid specimens were harvested and scanned using micro-computed tomography. Bone density (bone volume fraction) and bone quality (relative bone surface area, trabecular number, and trabecular thickness) were evaluated in 4 quadrants within each of the proximal and distal scaphoid. RESULTS: The proximal radial quadrant of the scaphoid had significantly greater bone volume than the distal ulnar (mean difference, 33.2%) and distal volar quadrants (mean difference, 32.3%). There was a significantly greater trabecular number in the proximal radial quadrant than in the distal ulnar (mean difference, 16.7%) and in the distal volar quadrants (mean difference, 15.9%) and between the proximal ulnar and the distal ulnar quadrants (mean difference, 12%). There was a significantly greater bone surface area in the proximal radial and distal radial quadrants than in the distal ulnar and distal volar quadrants. There were no significant differences in trabecular thickness between the 8 analyzed quadrants CONCLUSIONS: Although there are differences in bone volume, trabecular number, and bone surface area between the proximal pole of the scaphoid and that of the distal pole, there were no significant differences in the bone quality (trabecular thickness, trabecular number, and relative bone surface area) and density (bone volume fraction) between the 4 quadrants of the proximal or distal pole of the cadaveric scaphoids studied. CLINICAL RELEVANCE: Insertion of 2 headless compression screws can be determined by ease of surgical access and ease of screw positioning and not by differences in bone quality or density of the proximal or distal scaphoid.

Fixation of the Fractured Lunate in Kienböck Disease.

PURPOSE: To describe an uncommon subset of fractured lunates in Kienböck disease that is salvageable by internal fixation. METHODS: We performed a retrospective review for patients with Kienböck disease treated by internal fixation. Demographic data, objective and radiographic measurements, patient-reported outcome measures (Disabilities of the Arm, Shoulder, and Hand and Patient-Rated Wrist Evaluation) and pain (visual analog scale) scores were collected. RESULTS: Of the 7 patients treated, 5 were available for review. At an average follow-up of 7.1 years (range, 1.5-15 years), all patients had activity-related wrist pain but were pain-free at rest. Radiographic assessment showed union in all lunates and a normal radioscaphoid angle and Stahl index. The modified carpal height ratio was reduced in 4 patients and normal in one. There was no observed narrowing or irregularity of the radiocarpal or midcarpal joints. Patient-reported outcome measures in 2 patients were unsatisfactory. CONCLUSIONS: Computed tomography of the lunate in Kienböck disease is an important investigative tool. A coronal split fracture of these lunates can be salvageable by internal fixation. Revascularization of the lunate can be performed when the fragment is of sufficient size. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Propionibacterium Acnes Infection of a Metacarpophalangeal Joint Arthroplasty.

Neglected and underestimated in the past, Propionibacterium acnes is currently the most prevalent organism associated with deep prosthetic infections around the shoulder. Surprisingly, it has never been reported as a cause of infection in the hand. Here we report a case of a late presentation of a P. acnes infection in a metacarpophalangeal joint replacement, resulting in chronic low-grade pain with movement. The patient underwent a 2-stage revision, with initial removal of the prosthesis. Positive cultures for P. acnes required 15 days of extended incubation. The patient subsequently had 6 weeks of oral antibiotics followed by a second-stage revision with a Silastic implant.

Outcomes after operative treatment of elbow contractures in the pediatric and adolescent population.

BACKGROUND: The role of elbow contracture release in the very young is unclear, with existing studies reporting conflicting results. This study evaluated the long-term results after open elbow contracture release in patients aged younger than 18 years. METHODS: Between 1994 and 2012, 32 patients underwent open elbow contracture release at a mean age of 13.8 years (range, 5-18 years), and their outcomes were reviewed. The primary cause was traumatic in 30 patients (4 radial head/neck fractures, 5 intra-articular distal humeral fractures, 11 extra-articular distal humeral fractures, 10 complex fracture-dislocations), and the mean time from the index injury to contracture release was 16.3 months (range, 3-82 months). The cause in 2 patients was nontraumatic (1 osteochondritis dessicans, 1 congenital). The mean follow-up period was 66 months (range, 7-202 months). RESULTS: At the latest follow-up, total arc of motion improved from 69° to 123° (P <.0001), with a mean increase of 54° (P <.0001). The function arc was >100° in 28 patients (88%), and 29 patients (91%) achieved >20° of improvement in their arc. Twelve patients (38%) underwent a gentle manipulation under anesthesia at a mean of 2.7 weeks (range, 1-5 weeks) for early recurrence of stiffness. There were 3 complications (1 deep infection, 1 hematoma, 1 humeral fracture through the external fixator pin site). No patients lost motion after surgery. CONCLUSION: Elbow contracture release in the pediatric and adolescent population can provide significant improvements in range of motion similar to that achieved in adults. The improvements in motion are durable.

A Rare Case of Bipolar Clavicle Fracture.

Segmental or bipolar fractures of the clavicle generally refer to a concomitant ipsilateral distal clavicle and midshaft clavicle fracture. These injuries are exceedingly rare and are generally secondary to higher energy injuries. We report a case of a 38-year-old male who sustained a left bipolar clavicle fracture after falling from a push bike while riding recreationally which unusually involved the medial and lateral ends of the clavicle and not the midshaft as previously reported in other patients. The patient's exact fracture configuration was not immediately apparent highlighting the need for careful examination of the whole clavicle in order to not miss a bipolar fracture.

Surgical treatment of isolated type II superior labrum anterior-posterior (SLAP) lesions: repair versus biceps tenodesis.

BACKGROUND: It is still unclear which patients with isolated type II superior labrum anterior-posterior (SLAP) lesions benefit from either superior labral repair or biceps tenodesis. This study evaluates the indications and outcomes of patients with isolated type II SLAP lesions who have undergone either procedure. METHODS: A retrospective analysis was performed of patients who had surgery for an isolated type II SLAP lesion between 2008 and 2011. There were 25 patients: 15 underwent biceps tenodesis, with a mean follow-up of 31 months (range, 26-43 months), and 10 underwent SLAP repair, with a mean follow-up of 35 months (range, 25-52 months). The mean age was 47 years (range, 30-59 years) in the tenodesis group and 31 years (range, 21-43 years) in the repair group. RESULTS: At latest follow-up, both groups showed significant improvements in subjective shoulder value and pain score. No difference was observed in American Shoulder and Elbow Surgeons score (93.0 vs 93.5, P = .45), patient satisfaction (93% vs 90%, P = .45), or return to preinjury sporting level (73% vs 60%, P = .66). Analysis of the indications for treatment showed that in the large majority, tenodesis was performed in older patients (>35 years) and patients who showed degenerative or frayed labrums whereas SLAP repairs were performed in younger and more active patients with healthy-appearing labral tissue. There was only 1 failure in the tenodesis group, and in the SLAP repair group, there were 2 cases of postoperative stiffness; all were treated nonoperatively. CONCLUSION: In this study, we show that both biceps tenodesis and SLAP repair can provide good to excellent results if performed in appropriately selected patients with isolated type II SLAP lesions.

A comparative analysis of fatty infiltration and muscle atrophy in patients with chronic rotator cuff tears and suprascapular neuropathy.

BACKGROUND: Little is known of the mechanisms that lead to the muscle changes associated with rotator cuff disorders. We have observed that the magnetic resonance imaging (MRI) appearance of fatty infiltration (FI) and muscle atrophy (MA) differ between chronic cuff tears and suprascapular neuropathy, suggesting different pathophysiology. This study compares the different MRI changes that occur in chronic cuff tears and suprascapular neuropathy. METHODS: Two groups were retrospectively identified: (1) RCT group (20 shoulders): patients with chronic tears of the supraspinatus and/or infraspinatus without electromyographic (EMG) evidence of suprascapular neuropathy; (2) neuro group (17 shoulders): patients with EMG documented suprascapular nerve dysfunction and absence of a rotator cuff tear. Magnetic resonance arthrograms were analyzed for the degree of FI and MA, and the morphology of the muscle was assessed, in particular the muscle border, pattern of FI, and extent of involvement. RESULTS: The muscle changes that occur following chronic cuff tears differ from that following denervation secondary to suprascapular neuropathy, especially with respect to the muscle border, degree of perineural fat, and overall distribution of FI. Highly specific and characteristic morphological patterns of FI exist for both chronic cuff tears and suprascapular neuropathy. CONCLUSION: Chronic rotator cuff tendon tears and suprascapular neuropathy are both associated with FI and MA of the rotator cuff muscles. The pattern of FI is markedly different in the 2 situations. These findings have diagnostic potential and may serve as a basis for further research concerning type, severity, and evolution of FI under different conditions and after treatment.

Reverse total shoulder arthroplasty for massive irreparable rotator cuff tears in patients younger than 65 years old: results after five to fifteen years.

BACKGROUND: The role of reverse shoulder arthroplasty (RTSA) in the relatively young individual is currently unclear. Our study evaluates the midterm to long-term results of RTSA for patients aged younger than 65 years with pseudoparalysis secondary to massive irreparable rotator cuff tears, with or without arthritis. METHODS: Between 1997 and 2006, 46 RTSAs (41 patients) were performed. Mean age was 60 years (range, 46-64 years). At the latest follow-up, 5 patients had died and 1 was lost, leaving 35 patients (40 shoulders) with a mean follow-up of 93 months (range, 60-171 months). RESULTS: The mean relative Constant score increased from 34% to 74% (P < .0001) and the subjective shoulder value improved from 23% to 66% (P < .0001). Significant improvements were seen in active forward elevation (72° to 119°), pain scores, and strength (P < .001). One or more complications occurred in 15 shoulders (37.5%), with 6 failures (15%) resulting in removal or conversion to hemiarthroplasty (3 with infection, 3 with glenoid loosening). Ten shoulders (25%) underwent partial or total component exchange, conversion to hemiarthroplasty, or removal. Of the 15 patients who developed complications, 9 did not require prosthesis removal or conversion and functional outcome and subjective shoulder value were similar to those with no complications (P > .4). CONCLUSION: RTSA in younger patients provides significant subjective improvement and substantial gain in overall function, which is maintained up to 10 years. Although the complication rate is high, most can be treated successfully without compromise to clinical outcome. However, it is imperative that the high complication rate is explained to patients, with the risks and benefits carefully considered.

Accurate coracoid graft placement through use of a drill guide for the Latarjet procedure.

BACKGROUND: The Latarjet procedure has widely become the preferred treatment option for recurrent anterior glenohumeral instability in the presence of glenoid bone loss. The success of this procedure is largely dependent on accurate placement of the coracoid bone graft relative to the glenoid margin. With malpositioning of the coracoid graft, complications can arise, such as recurrent instability if placed too medially or impingement and subsequent early degenerative changes if positioned too laterally. To increase the accuracy and reproducibility of coracoid graft placement, we developed a simple and efficient drill guide that assists in accurate and safe positioning of the graft against the anterior glenoid to provide a congruent articular surface. MATERIALS AND METHODS: A new drill guide was used in 12 consecutive open Latarjet procedures. Accuracy of placement of the graft with respect to the anterior glenoid rim was assessed using postoperative computed tomography imaging. RESULTS: Accurate graft placement with a distance between the glenoid and the graft surface of less than 1 mm was obtained in all 12 interventions. The mean angulation of the screws relative to the glenoid face was 4.3° (range, 1°-7°). All screw heads were positioned medial to the articular edge of the graft, and the distance was always greater than 3 mm. CONCLUSIONS: The use of a simple drill guide allows safe and accurate graft placement during an open Latarjet procedure.

Isolated dislocation of the trapezoid.

Here we present a rare case of an isolated trapezoid dislocation secondary to a high-speed motor vehicle injury. In this case we highlight that the fact that these injuries are commonly missed on standard radiographs and management invariably requires open reduction and internal fixation.

Arthroscopic suture retrieval: a simple technique that disentangles sutures during retrieval.

Efficient and successful arthroscopic surgery relies on methodical and well-organized suture management. However, it is relatively common, especially in complex arthroscopic procedures, that sutures invariability become entangled or twisted as a result of repeated suture shuttling from portal to portal and between individual suture limbs. When this occurs, this can make antegrade suture passage or arthroscopic knot tying challenging. We describe a simple and efficient technique that allows simultaneous retrieval of 2 suture limbs while ensuring that the sutures are disentangled.

PEDF as an emerging therapeutic candidate for osteosarcoma.

Osteosarcoma (OS) is a disease that afflicts teenagers and adolescents in the prime of their lives. In spite of surgery and therapies currently used, there is a 1/3 chance of relapse. As for other cancers, current research is largely devoted to elucidating the molecular basis of the disease, with the anticipation that such research will lead to discovery and development of biological therapies. The major advantage of utilising such therapy is the relative lack of toxicity to normal tissues. One such enterprising candidate molecule, pigment epithelium-derived factor (PEDF), has recently been implicated to be involved in control of OS in orthotopic spontaneously metastasising models of the disease, whether administered as recombinant protein, overexpressed or administered as short peptides derived from the parent molecule. Expression of PEDF is inversely proportional to expression of vascular endothelial growth factor (VEGF) at the growth plate cartilage layer of growing bone in both mice and man. PEDF, originally discovered for its potent antiangiogenic activity, is now established as an anticancer factor with multiple mechanisms at its disposal for tumour inhibition. Current efforts are devoted to develop drug delivery systems, such as controlled release nanoparticles, that can be used to progress this potential drug candidate closer towards clinical trials for OS.