Preoperative Patient-Reported Outcomes Predict Postoperative Clinical Outcomes Following Rotator Cuff Repair

PURPOSE

To determine whether preoperative patient-reported outcomes (PROs) predict postoperative PROs and satisfaction following rotator cuff repair.

METHODS

We retrospectively identified patients who underwent a primary rotator cuff repair at a single institution. A receiver operating characteristics analysis was used to reach a preoperative American Shoulder and Elbow Surgeons (ASES) score threshold predictive of postoperative ASES and satisfaction scores. We evaluated patients above and below the receiver operating characteristics threshold by comparing their final ASES scores, ASES change (Δ) from baseline, percent maximum outcome improvement, and achievement of minimum clinically important differences, substantial clinical benefit (SCB), and patient-acceptable symptom state (PASS). Fischer exact tests were used to analyze categorical data, and continuous data were analyzed using t-test.

RESULTS

A total of 348 patients who underwent rotator cuff repair were included in this study. The preoperative ASES value predictive of achieving SCB was 63 (area under the curve, 0.75; 95% confidence interval: 58-67; P < .001). Patients with preoperative ASES less than 63 were significantly more likely to achieve MCID (odds ratio [OR]: 4.7, P < .001) and SCB (OR:6.1, P < .001) and had significantly higher percent maximum outcome improvement (63% vs 41%; P = 0.003) and Δ ASES scores (36 vs 12; P < .001). However, patients with preoperative ASES scores above 63 had significantly higher final ASES scores (86 vs 79; P = .003), were more likely to achieve PASS (59% vs 48%; P = .045), and had higher satisfaction scores (7.4 vs 6.7; P = .024).

CONCLUSIONS

Patients with high preoperative ASES scores achieve less relative improvement; however, these patients may be more likely to achieve PASS and may have higher satisfaction scores postoperatively. LEVEL OF EVIDENCE: Level III, retrospective comparative prognostic trial.

Guinea fowl eggshell structural analysis at different scales reveals how organic matrix induces microstructural shifts that enhance its mechanical properties

Guinea fowl eggshells have an unusual structural arrangement that is different from that of most birds, consisting of two distinct layers with different microstructures. This bilayered organization, and distinct microstructural characteristics, provides it with exceptional mechanical properties. The inner layer, constituting about one third of the eggshell thickness, contains columnar calcite crystal units arranged vertically as in most bird shells. However, the thicker outer layer has a more complex microstructural arrangement formed by a switch to smaller calcite domains with diffuse/interlocking boundaries, partly resembling the interfaces seen in mollusk shell nacre. The switching process that leads to this remarkable second-layer microstructure is unknown. Our results indicate that the microstructural switching is triggered by changes in the inter- and intracrystalline organic matrix. During production of the outer microcrystalline layer in the later stages of eggshell formation, the interactions of organic matter with mineral induce an accumulation of defects that increase crystal mosaicity, instill anisotropic lattice distortions in the calcite structure, interrupt epitaxial growth, reduce crystallite size, and induce nucleation events which increase crystal misorientation. These structural changes, together with the transition between the layers and each layer having different microstructures, enhance the overall mechanical strength of the Guinea fowl eggshell. Additionally, our findings provide new insights into how biogenic calcite growth may be regulated to impart unique functional properties. STATEMENT OF SIGNIFICANCE: Avian eggshells are mineralized to protect the embryo and to provide calcium for embryonic chick skeletal development. Their thickness, structure and mechanical properties have evolved to resist external forces throughout brooding, yet ultimately allow them to crack open during chick hatching. One particular eggshell, that of the Guinea fowl, has structural features very different from other galliform birds - it is bilayered, with an inner columnar mineral structure (like in most birds), but it also has an outer layer with a complex microstructure which contributes to its superior mechanical properties. This work provides novel and new fundamental information about the processes and mechanisms that control and change crystal growth during the switch to microcrystalline domains when the second outer layer forms.

Use of a Continuous Intracompartmental Pressure Monitoring Device During Fasciotomy

A 52-year-old man presented with a bicondylar tibial plateau fracture and acute compartment syndrome. Continuous compartment pressure monitoring was used while the patient was treated with fasciotomies and application of an external fixator. The intraoperative pressure reading in the anterior compartment decreased from 105 mm Hg to 50 mm Hg after skin and subcutaneous tissue incision. Pressure continued to decrease to 10 mm Hg after all 4 compartments were released. The patient underwent staged open reduction and internal fixation and healed both fracture and fasciotomy incisions without complication. To our knowledge, this is the first report of continuous pressure changes during the different stages of a compartment release. Future studies could expand on use of this technology to gain information on compartment pressures during release and how single release affects pressures in other compartments. [Orthopedics. 2024;47(2):e98-e101.].

Distal femur fractures: basic science and international perspectives

Distal femur fractures are challenging injuries to manage, and complication rates remain high. This article summarizes the international and basic science perspectives regarding distal femoral fractures that were presented at the 2022 Orthopaedic Trauma Association Annual Meeting. We review a number of critical concepts that can be considered to optimize the treatment of these difficult fractures. These include biomechanical considerations for distal femur fixation constructs, emerging treatments to prevent post-traumatic arthritis, both systemic and local biologic treatments to optimize nonunion management, the relative advantages and disadvantages of plate versus nail versus dual-implant constructs, and finally important factors which determine outcomes. A robust understanding of these principles can significantly improve success rates and minimize complications in the treatment of these challenging injuries.

Humerus fractures: selecting fixation for a successful outcome

Current evidence suggests at least one-third of humeral shaft fractures initially managed nonoperatively will fail closed treatment, and this review highlights surgical considerations in those circumstances. Although operative indications are well-defined, certain fracture patterns and patient cohorts are at greater risk of failure. When operative intervention is necessary, internal fixation through an anterolateral approach is a safe and sensible alternative. Determining which patients will benefit most involves shared decision-making and careful patient selection. The fracture characteristics, bone quality, and adequacy of the reduction need to be carefully evaluated for the specific operative risks for individuals with certain comorbid conditions, inevitably balancing the patient's expectations and demands against the probability of infection, nerve injury, or nonunion. As our understanding of the etiology and risk of nonunion and symptomatic malunion of the humeral diaphysis matures, adhering to the principles of diagnosis and treatment becomes increasingly important. In the event of nonunion, respect for the various contributing biological and mechanical factors enhances the likelihood that all aspects will be addressed successfully through a comprehensive solution. This review further explores specific strategies to definitively restore function of the upper extremity with the ultimate objective of an uninfected, stable union.

Clavicular Fractures in the Adolescent

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Current evidence suggests that the majority of clavicular fractures in adolescents can and should be treated nonoperatively.

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Although rare, in certain patients or fracture patterns, nonoperative management may be associated with delayed healing, prolonged disability, and/or poor functional outcome requiring secondary reconstruction.

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When warranted, primary open reduction and internal fixation with plate and screw application has consistently good outcomes with a low complication rate, with the most common complication being implant-related symptoms requiring a secondary surgical procedure for implant removal.

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Prospective, comparative studies examining operative and nonoperative treatment, including measures of early return to function, injury burden, return to athletic activity, complication and reoperation rates, and shoulder-girdle-specific, long-term outcome measures are warranted to further elucidate which fractures may benefit from primary fixation.

Compartment Syndrome: The Issues and Solutions You Need to Know About

The diagnosis and management of compartment syndrome remains challenging and controversial. There continues to be a significant burden of disease and substantial resource implications associated with fractures complicated by compartment syndrome. Achieving consensus opinions regarding the diagnosis and treatment of this problem has important implications given the profound effect on patient outcomes.

Threaded Intramedullary Nails Are Biomechanically Superior to Crossed K-wires for Metacarpal Neck Fractures

BACKGROUND

Intramedullary nail (IMN) fixation of metacarpal fractures is an alternative to Kirschner wire (K-wire) fixation. The goal of this study was to compare the biomechanical properties of K-wire fixation with a threaded IMN (InNate; ExsoMed, Aliso Viejo, California).

METHODS

The study design was based on previously described biomechanical models for evaluating metacarpal fractures. Sixteen fresh frozen small finger-matched and ring finger-matched pairs were randomized to either IMN or 0.045 in K-wire fixation after receiving a standardized neck osteotomy. Proper implant placement was confirmed with plain radiographs. Specimens then underwent loading in a 3-point bend configuration. Load to failure (LTF), stiffness, and fracture displacement were recorded. Mechanical failure was defined by a sharp change in the load-displacement curve.

RESULTS

Age, sex, sidedness (left or right), and digit (ring or small finger) were evenly distributed between groups. The IMN had a significantly higher LTF than K-wires (546 N vs 154 N, P < .001). The K-wire fixation demonstrated plastic deformation between 75 and 150 N. Intramedullary nail stiffness was higher than that of K-wires (155.89 N/mm vs 59.28 N/mm, P < .001).

CONCLUSIONS

When surgical fixation is indicated for metacarpal neck and shaft fractures, the threaded IMN is biomechanically superior to crossed K-wires with the application of 3-point bend.

Proximal Humerus Fractures: Leave It Alone, Fix It, Replace It?

Proximal humerus fractures are common injuries that account for 10% of all fractures in the elderly. Several options are available for the management of proximal humerus fractures. Optimal treatment is based on the fracture pattern and the patient characteristics. Most of these fractures are minimally displaced and managed nonsurgically. Approximately 15% of proximal humerus fractures are comminuted, head-split, fracture-dislocation, or severely displaced, which make the best treatment option more challenging. Hemiarthroplasty is still a viable option in selected patients of these groups; however, advancements in locking plate designs and introduction of reverse total shoulder arthroplasty have led to better clinical outcome in meticulously selected patients. Nonetheless, the debate continues regarding the best management. It is important to discuss the best treatment options based on current literature.

Biomechanical comparison of tuberosity-based proximal humeral locking plate compared to standard proximal humeral locking plate in varus cantilever bending

PURPOSE

In a prior biomechanical study using a tuberosity-based proximal humeral locking plate (TBP) an improvement in greater tuberosity (GT) fixation strength with the TBP compared to a standard proximal humeral locking plate (PHLP) was demonstrated. The purpose of this study is to compare the TBP to the PHLP with a simulated calcar gap fracture under cyclic varus cantilever forces.

METHODS

Seven matched pairs of cadaveric humeri were studied and 11A2.3 proximal humerus fractures were created by a 1 cm gap osteotomy at the surgical neck. Matched pairs were randomized for fixation using either a PHLP or a TBP. The proximal articular aspect of the humerus was potted and secured to the base of a load frame. The shaft was subjected to cyclic varus cantilever loading with a roller positioned 8 cm from the osteotomy. Change in vertical displacement of the diaphyseal fragment was monitored and digital images were obtained. Failure was defined as vertical displacement greater than 20 mm. Specimens not exhibiting failure over the course of 10,000 cycles were then loaded to 20 mm of vertical displacement. Reactant forces of the specimens at these displacements were recorded.

RESULTS

Four/seven TBP specimens and four/seven PHLP specimens survived 10,000 cycles. The average cycles to failure for TBP specimens was 7325 cycles and 5715 cycles for PHLP specimens (p = 0.525). For the specimens that survived 10,000 cycles, the decrease in calcar gap was superior in the TBP specimens (p = 0.018). A similar trend was seen when these specimens were loaded to failure where the percent calcar gap recovery was higher for the TBP at 74.71 ± 10.07% versus 53.22 ± 30.35% for the PHLP (p = 0.072). In specimens that were loaded to failure after survival of 10,000 cycles the average stiffness of the TBP construct was 20.51 N/mm, and 11.74 N/mm for the PHLP construct (p = 0.024).

CONCLUSION

In addition to superior GT fixation shown in a prior study, the TBP construct demonstrates significantly greater stiffness at the neck fracture compared to the PHLP, when loaded to failure. In addition, there was a trend towards less collapse in this calcar gap model.

Development and Internal Validation of Novel Risk Tools to Predict Subsequent Shoulder Surgery After Proximal Humerus Fractures

OBJECTIVE

To (1) identify predictors of subsequent surgery after initial treatment of proximal humerus fractures (PHFs) and (2) generate valid risk prediction tools to predict subsequent surgery.

METHODS

We identified patients ≥50 years with PHF from 2004 to 2015 using health data sets in Ontario, Canada. We used procedural codes to classify patients into treatment groups of (1) surgical fixation, (2) shoulder replacement, and (3) conservative. We used procedural and diagnosis codes to capture subsequent surgery within 2 years after fracture. We developed regression models for two-thirds of each group to identify predictors of subsequent surgery and the regression equations to develop risk tools to predict subsequent surgery. We used the final third of each cohort to evaluate the discriminative ability of the risk tools using c-statistics.

RESULTS

We identified 20,897 patients with PHF, 2414 treated with fixation, 1065 with replacement, and 17,418 treated conservatively. Predictors of reoperation after fixation included bone grafting and nail or wire fixation versus plate fixation, whereas poor bone quality was associated with reoperation after initial replacement. In conservatively treated patients, more comorbidities were associated with subsequent surgery, whereas age 70+ and discharge home after presentation lowered the odds of subsequent surgery. The risk tools were able to discriminate with c-statistics of 0.75-0.88 (derivation) and 0.51-0.79 (validation).

CONCLUSIONS

Our risk tools showed good to strong discriminative ability for patients treated conservatively and with fixation. These data may be used as the foundation to develop a clinically informative tool.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Decreasing Trend in Complications for Patients With Obesity and Metabolic Syndrome Undergoing Total Knee Arthroplasty From 2006 to 2017

BACKGROUND

To describe longitudinal trends in patients with obesity and Metabolic Syndrome (MetS) undergoing total knee arthroplasty (TKA) and the impact on complications.

METHODS

We identified primary TKA patients between 2006 and 2017 within the National Surgical Quality Improvement Program database. We recorded patient demographics and 30-day complications. We labeled those with an obese Body Mass Index (BMI ≥30), hypertension, and diabetes as having MetS. We used regression to evaluate trends in BMI and complications over time and variables associated with the odds of complication.

RESULTS

We identified 270,846 TKA patients, 63.71% of which were obese (n = 172,333), 15.21% morbidly obese (n = 41,130), and 12.37% met the criteria for MetS (n = 33,470). Mean BMI increased by 0.03 per year (0.02-0.05). Despite this, the odds of adverse events in obese patients decreased: major complications by 0.94 (0.93-0.96) and minor complications by 0.94 (0.93-0.95). The proportion of patients with MetS remained stable; however, we found improvements in major (0.94 [0.91-0.97]) and minor complications (0.97 [0.94-1.00]) over time. MetS components (hypertension, diabetes, and BMI ≥40) were associated with major and minor complications in obese patients, while neuraxial anesthesia lowered the odds of major complications in obese patients (0.87 [0.81-0.92]).

CONCLUSION

Mean BMI in primary TKA patients increased from 2006 to 2017. MetS components diabetes and hypertension elevated the odds of complications in obese patients. Rates of complications in patients with obesity and MetS exhibited a longitudinal decline. These findings may reflect increased awareness and improved management of these patients.

Elbow Trauma: An Evidence-Based Approach to Improving Outcomes

The management of elbow fractures remains difficult and controversial. The failure rate of surgical intervention in elbow fractures remains higher than that seen with other fractures, and there remains significant room for improvement in the care of these injuries. Evidence-based management strategies for elbow fractures and how to prevent and manage complications following elbow fracture surgery have been described.

Operative Versus Nonoperative Treatment of Acute Displaced Distal Clavicle Fractures: A Multicenter Randomized Controlled Trial

OBJECTIVES

To evaluate the differences in patient outcomes after operative or nonoperative treatment of displaced, type II distal clavicle fractures.

DESIGN

Multicenter, prospective, randomized controlled trial.

SETTING

Level I trauma centers.

PATIENTS/PARTICIPANTS

Patients with completely displaced type II distal clavicle fractures were included. Fifty-seven patients were randomized: 27 to the operative group and 30 to the nonoperative group.

INTERVENTION

Patients randomized to nonoperative care received a standard shoulder sling, followed by pendulum or gentle range of motion shoulder exercises at any time as directed by the attending surgeon. Patients randomized to the operative group received plate fixation with a precontoured distal clavicular plate or a "hook" plate within 28 days from injury.

MAIN OUTCOME MEASURE

Disabilities of the Arm, Shoulder and Hand scores at 1 year.

RESULTS

There were no between-group differences in Disabilities of the Arm, Shoulder and Hand or Constant scores at 1 year. More patients in the operative group went on to union (95% vs. 64%, P = 0.02) within 1 year. Twelve patients in the operative group underwent a second operation for implant removal (12/27, 44%). In the nonoperative group, 6 patients (6/30, 20%) subsequently underwent 8 operative procedures.

CONCLUSION

Although this study failed to demonstrate a difference in functional outcomes between operative and nonoperative treatment of Neer type II distal clavicle fractures, nonoperative management led to more complications including a moderate rate of nonunion, which often required secondary surgery to correct, a higher rate of early dissatisfaction with shoulder appearance, and a delayed return to activities in the first 6 months. Operative management provided a safe and reliable treatment option with few complications, but often required secondary implant removal, especially with hook plate fixation.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

In Situ Placement Versus Anterior Transposition of the Ulnar Nerve for Distal Humerus Fractures Treated With Plate Fixation: A Multicenter Randomized Controlled Trial

OBJECTIVES

To compare clinical scores and electrodiagnostic evidence of ulnar neuropathy, between ulnar nerve mobilization and placement back in the cubital tunnel versus anterior transposition, during plate and screw fixation of a bicolumnar fracture of the distal humerus.

DESIGN

Multicenter randomized controlled trial.

SETTING

Eight tertiary care centres in Canada.

PATIENTS

Fifty-eight patients with distal humerus fractures undergoing plate fixation of both columns were recruited and randomized.

INTERVENTION

All patients underwent bicolumnar plate fixation for an acute, displaced fracture of the distal humerus with identification, mobilization, and protection of the ulnar nerve as part of the surgical approach. At the conclusion of the procedure, they were randomized to either (1) replacing the nerve in situ in the cubital tunnel or (2) anterior transposition.

MAIN OUTCOME MEASUREMENTS

The primary outcome was the Gabel & Amadio rating scale for ulnar neuropathy. Secondary outcomes included a functional outcome score (Mayo Elbow Performance Score), disabilities of the arm, shoulder and hand instrument, 2-point discrimination, nerve conduction testing, complications, and secondary surgeries.

RESULTS

Thirty-one patients were randomized to in situ placement and 27 to anterior transposition. The mean age was 53 years, and 60% were women. There was no difference between the 2 groups with regards to age, gender, body mass index, smoking, diabetes, injury characteristics, time to operation, length of operation, or surgical approach. There was no difference in outcome between the 2 groups at any time point with regards to Gabel & Amadio ulnar neuropathy scores, Mayo Elbow Performance Score, disabilities of the arm, shoulder and hand instrument, or 2-point discrimination. The incidence of ulnar nerve dysfunction, as measured by use of the Gabel & Amadio ulnar neuropathy score, was poor in both groups acutely; however, there was significant improvement at 12 months postoperatively (6.0-7.8, P < 0.001).

CONCLUSIONS

This study was unable to demonstrate any significant difference in outcomes when comparing ulnar nerve mobilization and in situ placement and anterior subcutaneous transposition after bicolumnar plate fixation of a distal humerus fracture. Either strategy for managing the ulnar nerve is acceptable and can be used at the discretion of the treating surgeon.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Biological stenciling of mineralization in the skeleton: Local enzymatic removal of inhibitors in the extracellular matrix

Biomineralization is remarkably diverse and provides myriad functions across many organismal systems. Biomineralization processes typically produce hardened, hierarchically organized structures usually having nanostructured mineral assemblies that are formed through inorganic-organic (usually protein) interactions. Calcium‑carbonate biomineral predominates in structures of small invertebrate organisms abundant in marine environments, particularly in shells (remarkably it is also found in the inner ear otoconia of vertebrates), whereas calcium-phosphate biomineral predominates in the skeletons and dentitions of both marine and terrestrial vertebrates, including humans. Reconciliation of the interplay between organic moieties and inorganic crystals in bones and teeth is a cornerstone of biomineralization research. Key molecular determinants of skeletal and dental mineralization have been identified in health and disease, and in pathologic ectopic calcification, ranging from small molecules such as pyrophosphate, to small membrane-bounded matrix vesicles shed from cells, and to noncollagenous extracellular matrix proteins such as osteopontin and their derived bioactive peptides. Beyond partly knowing the regulatory role of the direct actions of inhibitors on vertebrate mineralization, more recently the importance of their enzymatic removal from the extracellular matrix has become increasingly understood. Great progress has been made in deciphering the relationship between mineralization inhibitors and the enzymes that degrade them, and how adverse changes in this physiologic pathway (such as gene mutations causing disease) result in mineralization defects. Two examples of this are rare skeletal diseases having osteomalacia/odontomalacia (soft bones and teeth) - namely hypophosphatasia (HPP) and X-linked hypophosphatemia (XLH) - where inactivating mutations occur in the gene for the enzymes tissue-nonspecific alkaline phosphatase (TNAP, TNSALP, ALPL) and phosphate-regulating endopeptidase homolog X-linked (PHEX), respectively. Here, we review and provide a concept for how existing and new information now comes together to describe the dual nature of regulation of mineralization - through systemic mineral ion homeostasis involving circulating factors, coupled with molecular determinants operating at the local level in the extracellular matrix. For the local mineralization events in the extracellular matrix, we present a focused concept in skeletal mineralization biology called the Stenciling Principle - a principle (building upon seminal work by Neuman and Fleisch) describing how the action of enzymes to remove tissue-resident inhibitors defines with precision the location and progression of mineralization.

An evaluation of treatment options for medial, midshaft, and distal clavicle fractures: a systematic review and meta-analysis

Background

The majority of clavicle fractures are midshaft injuries, although fractures of the distal or medial fragment also occur. The aim of this study was to review the current evidence on these injuries to help inform future treatment plans.

Methods

We searched for studies comparing interventions for medial, midshaft, or distal clavicle fractures; however, we did not identify any comparative studies on medial fractures and performed a secondary search on this topic. We conducted Bayesian network meta-analyses, although this was not feasible with studies on medial fractures and we described their results qualitatively.

Results

For midshaft fractures, we found statistically significant improvements in function and time to radiographic union with plating, an elastic stable intramedullary nail (ESIN), and the Sonoma CRx intramedullary nail over nonoperative treatments. Both plating and an ESIN also showed significantly lower risks of nonunion and malunion relative to nonoperative methods. For distal fractures, a locking plate (LP) with or without coracoclavicular (CC) suturing yielded significantly better outcomes over K-wires with or without tension bands, CC suturing alone, an LP with a CC screw, a hook plate, and a sling. For medial fractures, plating may result in more favorable functional and union-related outcomes, although implant irritation may occur. In addition, K-wires, tension bands, and a screw with sutures demonstrated success when plating was technically not feasible in a few cases, whereas treatment with a sling may result in reduced function and a higher risk of complications relative to surgery.

Conclusion

This study can provide guidance on the management of medial, midshaft, and distal clavicle fractures. The current evidence suggests that plating, an ESIN, and a CRx intramedullary nail are all good options for midshaft fractures; an LP with or without CC suturing should be preferred for distal fractures; and plating is also acceptable for medial fractures, provided that the patient is deemed suitable for surgery and has the adequate bone stock and sufficiently sized medial fragment necessary to implant the device. Patient preferences for certain outcomes should be considered, which may result in different treatment recommendations.

Irreducible Volar DRUJ Dislocation with Distal Radius Fracture Dislocation

Background  Volar dislocations of the distal radioulnar joint (DRUJ) are rare and often missed during initial evaluation. Chronic dislocations and disability can occur when DRUJ dislocations are unrecognized and not reduced. DRUJ dislocations often occur with other wrist injuries, which may complicate reduction. Closed reduction can fail to reduce DRUJ dislocations, in which case open reduction is necessary. Case Description  This case describes a patient who had a volar dislocation of the DRUJ with an associated dorsal distal radius fracture dislocation. Initial attempts at closed reduction were unsuccessful which prompted surgical intervention. After open reduction and internal fixation of the distal radius fracture dislocation, closed reduction of the DRUJ remained unsuccessful. This prompted an open reduction of the DRUJ. Surgical exposure demonstrated that the extensor carpi ulnaris and the distal radius had prevented closed reduction of the DRUJ. Postoperatively, a splint was placed with the wrist in supination. The patient followed-up at the 2- and 4-month intervals with persistent subluxation. However, the patient also reported minimal pain and the ability to return to work and previous level of activity. Literature Review  Current literature regarding irreducible volar DRUJ dislocations with distal radius fracture dislocations includes sparse case reports, which are reviewed in this report. Clinical Relevance  This case illustrates successful treatment for an uncommon volar DRUJ dislocation associated with a dorsal distal radius fracture dislocation and can be utilized to help guide future treatment of similar complex cases.

A higher reoperation rate following arthroplasty for failed fixation versus primary arthroplasty for the treatment of proximal humeral fractures

Aims

To compare complication-related reoperation rates following primary arthroplasty for proximal humerus fractures (PHFs) versus secondary arthroplasty for failed open reduction and internal fixation (ORIF).

Patients and Methods

We identified patients aged 50 years and over, who sustained a PHF between 2004 and 2015, from linkable datasets. We used intervention codes to identify patients treated with initial ORIF or arthroplasty, and those treated with ORIF who returned for revision arthroplasty within two years. We used multilevel logistic regression to compare reoperations between groups.

Results

We identified 1624 patients who underwent initial arthroplasty for PHF, and 98 patients who underwent secondary arthroplasty following failed ORIF. In total, 72 patients (4.4%) in the primary arthroplasty group had a reoperation within two years following arthroplasty, compared with 19 patients (19.4%) in the revision arthroplasty group. This difference was significantly different (p < 0.001) after covariable adjustment.

Conclusion

The number of reoperations following arthroplasty for failed ORIF of PHF is significantly higher compared with primary arthroplasty. This suggests that primary arthroplasty may be a better choice for patients whose prognostic factors suggest a high reoperation rate following ORIF. Prospective clinical studies are required to confirm these findings. Cite this article: Bone Joint J 2019;101-B:1272–1279

NASHA hyaluronic acid for the treatment of shoulder osteoarthritis: a prospective, single-arm clinical trial

Background: Osteoarthritis of the shoulder or glenohumeral joint is a painful condition that can be debilitating. Intra-articular injection with hyaluronic acid should be considered for patients not responding adequately to physical therapy or anti-inflammatory medication.

Methods: This was a single-arm, open-label, prospective study of a single intra-articular injection of NASHA (non-animal hyaluronic acid) in patients with symptomatic glenohumeral osteoarthritis. Patients were followed up for 26 weeks post-treatment, during which time rescue medication with acetaminophen was permissible. The study objective was to demonstrate that a single injection of NASHA is well tolerated with an over-6-month 25% reduction in shoulder pain on movement, assessed using a 100-mm visual analog scale.

Results: Forty-one patients were enrolled, all of whom received study treatment. The mean decrease in shoulder pain on movement score over the 6-month study period was −20.1 mm (95% CI: −25.2, −15.0 mm), corresponding to a mean reduction of 29.5% (22.0, 37.0%). Statistically significant improvements were also observed in shoulder pain at night and patient global assessment. There was no clear change over time in the percentage of patients using rescue medication and mean weekly doses were below 3500 mg. Seventeen patients (41.5%) experienced adverse events, all of which were mild or moderate. Two adverse events (both shoulder pain) were deemed related to study treatment.

Conclusion: This study provides preliminary evidence that a single injection of NASHA may be efficacious over 6 months and well tolerated in patients with symptomatic glenohumeral osteoarthritis. Larger studies are needed for confirmation.

Clavicle Trauma: From Acromioclavicular Joint Injuries to Distal Clavicle Fractures and Midshaft Fractures in Contact Athletes

Injuries to the clavicle and its articulations (the acromioclavicular and sternoclavicular joints) are becoming increasingly common. Conventional treatment has been dominated by nonsurgical techniques; however, the active patient was often left with substantial residual disability that was underreported. It is now recognized that surgical intervention may be advantageous in specific patients, especially athletes. Surgeons should consider pathophysiology, indications, and surgical techniques to best manage these injuries.

Plate fixation for management of humerus fractures

Proximal humerus, humeral shaft, and distal humerus fractures are all common adult fractures, and often occur in older patients. While the treatment of proximal humerus fractures remains controversial, certain fractures benefit from plate fixation such as fracture-dislocations and head-split fractures. When plate fixation is chosen, anatomic reduction and restoration of the medial calcar are important for successful results. Further research is required to minimize complications and determine the optimal surgical candidates for plate fixation. Humeral shaft fractures are generally treated non-operatively. However, certain shaft fractures warrant plate fixation, such as open fractures, those with associated forearm fractures, and those in poly-trauma patients. Choice of surgical approach and plate depends on the location and type of the fracture. The majority of intra-articular distal humerus fractures should be treated with plate fixation. Dual plating is generally accepted as the gold standard treatment, while the optimal surgical approach and plate configuration requires more research.

Bone toughness at the molecular scale: A model for fracture toughness using crosslinked osteopontin on synthetic and biogenic mineral substrates

The most prominent structural components in bone are collagen and mineral. However, bone additionally contains a substantial amount of noncollagenous proteins (most notably of the SIBLING protein family), some of which may act as cohesive/adhesive "binders" for the composite hybrid collagen/mineral scaffolding, whether in the bulk phase of bone, or at its interfaces. One such noncollagenous protein - osteopontin (OPN) - appears to be critical to the deformability and fracture toughness of bone. In the present study, we used a reconstructed synthetic mineral-OPN-mineral interface, and a biogenic (natural tooth dentin) mineral/collagen-OPN-mineral/collagen interface, to measure the fracture toughness of OPN on mineralized substrates. We used this system to test the hypothesis that OPN crosslinking by the enzyme tissue transglutaminase 2 (TG2) that is found in bone enhances interfacial adhesion to increase the fracture toughness of bone. For this, we prepared double-cantilever beam substrates of synthetic pure hydroxyapatite mineral, and of narwhal dentin, and directly apposed them to one another under different intervening OPN/crosslinking conditions, and fracture toughness was tested using a miniaturized loading stage. The work-of-fracture of the OPN interface was measured for different OPN formulations (monomer vs. polymer), crosslinking states, and substrate composition. Noncrosslinked OPN provided negligible adhesion on pure hydroxyapatite, whereas OPN crosslinking (by the chemical crosslinker glutaraldehyde, and TG2 enzyme) provided strong interfacial adhesion for both hydroxyapatite and dentin using monomeric and polymeric OPN. Pre-coating of the substrate beams with monomeric OPN further improved the adhesive performance of the samples, likely by allowing effective binding of this nascent OPN form to mineral/matrix components, with this pre-attachment providing a protein layer for additional crosslinking between the substrates.

Open Reduction and Internal Fixation Versus Acute Arthroplasty for the Management of Common Extremity Injuries: Evidence-Based Decision Making

A considerable burden of disease is associated with the management of periarticular fractures. Increasingly, evidence-based medicine is used to define the standard of clinical care. The role of internal fixation in the management of periarticular fractures, particularly in elderly patients, has been questioned. Currently available evidence-based medicine studies may help surgeons decide whether open reduction and internal fixation or arthroplasty is appropriate for the management of common periarticular injuries. The management of periarticular injuries about the shoulder, elbow, hip, and knee is controversial. The long-term outcomes of patients with a periarticular upper or lower extremity injury who undergo open reduction and internal fixation are limited by high complication and revision surgery rates and poor functional outcomes. Despite evidence-based medicine decision making and the substantial number of prospective clinical trials available in the literature, a lack of consensus with regard to best practices for the surgical management of periarticular injuries exists. This lack of consensus has substantial implications given that proximal humerus, elbow, hip, and knee fractures are common and that the role of acute arthroplasty in the management of periarticular injuries is changing.

An international, cross-sectional survey of the management of Vancouver type B1 periprosthetic femoral fractures around total hip arthroplasties

INTRODUCTION

The incidence of periprosthetic femoral fractures around total hip arthroplasties is increasing. Fractures around a stable implant stem (Vancouver type B1) are among the most common of these fractures. Various fixation strategies for Vancouver type B1 periprosthetic fractures have been reported in the literature; however, little high-level evidence exists. This study was designed to determine the current management strategies and opinions among orthopaedic surgeons treating Vancouver type B1 periprosthetic femoral fractures, and to evaluate the need for a large prospective randomized controlled trial for the management of these injuries.

METHODS

Orthopaedic surgeon members of the Orthopaedic Trauma Association (OTA), the Canadian Orthopaedic Association (COA), and the Hip Society were invited to participate in a 51-item web-based survey surrounding the management of periprosthetic femoral fractures around total hip replacements, as well as the perceived need for future research in this area. Responses were summarized using proportions, and further stratified by practice type, case volume, surgeon age, and fellowship training.

RESULTS

For Vancouver type B1 fractures, open reduction and internal fixation (ORIF) with locked plating was favoured slightly over ORIF with cable plating ± cortical strut allograft (51.1% versus 45.5%). When compared to cable plating with cortical strut allograft, respondents believed that isolated locked plating resulted in lower nonunion and reoperation rates, but similar infection and malunion rates. Subgroup analyses revealed that practice type, surgeon age, case volume, and fellowship training influenced surgeons' management of periprosthetic femoral fractures and beliefs regarding complications. There is high demand for a large prospective randomized controlled trial for Vancouver type B1 fracture fixation.

CONCLUSIONS

Consensus surrounding the management of Vancouver type B1 periprosthetic femoral fractures is lacking, and there is a perceived need among orthopaedic surgeons for a large prospective randomized controlled trial in order to define the optimal management of these injuries.

Clavicle Malunions: Surgical Treatment and Outcome-a Literature Review

BACKGROUND

Successful treatment of clavicle malunion represents a major challenge for orthopedic surgeons.

QUESTIONS/PURPOSES

The aim of this study was to provide an overview of surgical options for the treatment of clavicle malunions regarding their technical details and clinical results.

METHODS

A comprehensive search of the literature was performed to retrieve articles and conference abstracts regarding the surgical treatment of clavicle malunions. A total of 1873 records were identified and 29 studies were included in the present review, with a total of 103 patients.

RESULTS

The majority of the patients (77/103) were treated with an osteotomy and subsequent open reduction internal fixation (ORIF). The next most frequent management choice was debridement, excision, or removal of excess callus or bone (n = 19), but other techniques like resection of the clavicle (n = 5) or nerve exploration and decompression (n = 2) were also reported. The preferred method of fixation was plate fixation (n = 53) followed by pin fixation (n = 6). The complication rate was low, reported in less than 6% of patients.

CONCLUSION

All of the currently reported surgical techniques to manage symptomatic clavicle malunion have resulted in good clinical outcomes with a low complication rate. Considering biomechanical aspects, correction osteotomy followed by plate fixation seems to be the preferred method. Further studies are needed to compare the various surgical techniques and their specific outcomes in a prospective manner. Nevertheless, this review article can be used as an overview to help choose an optimal operative treatment for patients presenting with a clavicle malunion.

Defective Mineralization in X-Linked Hypophosphatemia Dental Pulp Cell Cultures

X-linked hypophosphatemia (XLH) is a skeletal disease caused by inactivating mutations in the PHEX gene. Mutated or absent PHEX protein/enzyme leads to a decreased serum phosphate level, which cause mineralization defects in the skeleton and teeth (osteomalacia/odontomalacia). It is not yet altogether clear whether these manifestations are caused solely by insufficient circulating phosphate availability for mineralization or also by a direct, local intrinsic effect caused by impaired PHEX activity. Here, we evaluated the local role of PHEX in a 3-dimensional model of extracellular matrix (ECM) mineralization. Dense collagen hydrogels were seeded either with human dental pulp cells from patients with characterized PHEX mutations or with sex- and age-matched healthy controls and cultured up to 24 d using osteogenic medium with standard phosphate concentration. Calcium quantification, micro-computed tomography, and histology with von Kossa staining for mineral showed significantly lower mineralization in XLH cell-seeded scaffolds, using nonparametric statistical tests. While apatitic mineralization was observed along collagen fibrils by electron microscopy in both groups, Raman microspectrometry indicated that XLH cells harboring the PHEX mutation produced less mineralized scaffolds having impaired mineral quality with less carbonate substitution and lower crystallinity. In the XLH cultures, immunoblotting revealed more abundant osteopontin (OPN), dentin matrix protein 1 (DMP1), and matrix extracellular phosphoglycoprotein (MEPE) than controls, as well as the presence of fragments of these proteins not found in controls, suggesting a role for PHEX in SIBLING protein degradation. Immunohistochemistry revealed altered OPN and DMP1 associated with an increased alkaline phosphatase staining in the XLH cultures. These results are consistent with impaired PHEX activity having local ECM effects in XLH. Future treatments for XLH should target both systemic and local manifestations.

Prospective Randomized Clinical Trial Investigating the Effect of the Reamer-Irrigator-Aspirator on the Volume of Embolic Load and Respiratory Function During Intramedullary Nailing of Femoral Shaft Fractures

OBJECTIVES

We sought to determine whether the use of the Reamer-Irrigator-Aspirator (RIA) device resulted in a decreased amount of fat emboli compared with standard reaming (SR) when performing intramedullary (IM) nailing of femoral shaft fractures.

DESIGN

Prospective randomized clinical trial.

SETTING

Multi-centered trial, level I trauma centers.

PATIENTS/PARTICIPANTS

All eligible patients who presented to participating institutions with an isolated femoral shaft fracture amenable to fixation with antegrade IM nailing. Thirty-one patients were enrolled: nine were excluded because of technical difficulties with the transesophageal echocardiogram (TEE) recording. Therefore, the study comprised 22 patients: 11 patients randomized to the SR group and eleven patients randomized to the RIA group.

INTERVENTION

Antegrade IM nailing of a femoral shaft fracture with standard reamers or the RIA device. All patients were monitored intraoperatively with a continuous TEE to assess embolic events in the right atrium. A radial arterial line was used to monitor blood gases and potential systemic effects of emboli.

MAIN OUTCOME MEASURE

Duration, size, and severity of emboli as measured by TEE. The operative procedure was divided into 6 distinct stages: preoperative, reduction, guidewire passage, reaming, nail insertion, and postoperative.

RESULTS

There was no significant difference in emboli between the RIA and SR groups preoperatively, during fracture reduction, guidewire insertion, or postoperatively. Measured with a standardized scoring system, there was a modest reduction in total emboli score in the RIA group during reaming (SR 5.30 [SD; 1.81] vs. RIA 4.05 [SD; 2.19], P = 0.005) and during nail insertion (SR 5.09 [SD; 1.74] vs. RIA 4.25 [SD; 1.89], P = 0.03). We were unable to correlate this reduction with any improvement in physiologic parameters (mean arterial pressure, end-tidal CO2, O2 saturation, pH, paO2, and paCO2).

CONCLUSIONS

This study showed a modest reduction of embolic debris during the reaming and nail insertion segments of the operative procedure. We were unable to correlate this with any change in physiologic parameters.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Total hip arthroplasty following failure of core decompression and tantalum rod implantation

AIMS

One method of femoral head preservation following avascular necrosis (AVN) is core decompression and insertion of a tantalum rod. However, there may be a high failure rate associated with this procedure. The purpose of this study was to document the clinical and radiological outcomes following total hip arthroplasty (THA) subsequent to failed tantalum rod insertion.

PATIENTS AND METHODS

A total of 37 failed tantalum rods requiring total hip arthroplasty were identified from a prospective database. There were 21 hips in 21 patients (12 men and nine women, mean age 37 years, 18 to 53) meeting minimum two year clinical and radiographic follow-up whose THAs were carried out between November 2002 and April 2013 (mean time between tantalum rod implantation and conversion to a THA was 26 months, 6 to 72). These were matched by age and gender to individuals (12 men, nine women, mean age 40 years, 18 to 58) receiving THA for AVN without prior tantalum rod insertion.

RESULTS

There were no functional outcome differences between the two groups. Tantalum residue was identified on all post-operative radiographs in the tantalum group. Linear wear rates were comparable between groups with no evidence of catastrophic wear in either group.

CONCLUSION

In the short term, tantalum rod implantation does not demonstrate an adverse effect on subsequent total joint replacement surgery. There is however, a high rate of retained tantalum debris on post-operative radiographs and thus there is an unknown risk of accelerated articular wear necessitating longer term study. Cite this article: Bone Joint J 2016;98-B:1175-9.

Transglutaminase Crosslinking of SIBLING Proteins in Teeth

Transglutaminase 2 (TG2), a protein-crosslinking enzyme, participates in extracellular matrix maturation and cell adhesion in cartilage and bone. We hypothesized that TG2 has similar roles in teeth. A TG activity assay and immunoblotting of rat tooth extracts showed TG activity and the presence of high-molecular-weight forms of the SIBLING (Small Integrin-Binding LIgand N-linked Glycoprotein) proteins: dentin matrix protein 1 (DMP1), dentin phosphoprotein (DPP), and bone sialoprotein (BSP). DMP1 and BSP, each containing both glutamine and lysine residues critical for crosslink formation, readily formed polymers in vitro when incubated with TG2. The ability of glutamine-lacking DPP to form polymers in vitro and in vivo demonstrates that it could act as a lysine donor for crosslinking, potentially having protein crosslinking partner(s) in teeth. Consistent with a role in cell adhesion, the TG2 isoform was co-localized by immunohistochemistry with its substrates at cell-matrix adhesion sites, including along odontoblast tubules (DMP1 and DPP), in the pericellular matrix of cementocytes (DMP1), and in predentin (BSP).

Are patients willing to pay for total shoulder arthroplasty? Evidence from a discrete choice experiment

BACKGROUND

Total shoulder arthroplasty (TSA) is a common treatment to decrease pain and improve shoulder function in patients with severe osteoarthritis (OA). In Canada, patients requiring this procedure often wait a year or more. Our objective was to determine patient preferences related to accessing TSA, specifically comparing out-of-pocket payments for treatment, travel time to hospital, the surgeon's level of experience and wait times.

METHODS

We administered a discrete choice experiment among patients with endstage shoulder OA currently waiting for TSA. Respondents were presented with 14 different choice sets, each with 3 options, and they were asked to choose their preferred scenario. A conditional logit regression model was used to estimate the relative preference and willingness to pay for each attribute.

RESULTS

Sixty-two respondents completed the questionnaire. Three of the 4 attributes significantly influenced treatment preferences. Respondents had a strong preference for an experienced surgeon (mean 0.89 ± standard error [SE] 0.11), while reductions in travel time (-0.07 ± 0.04) or wait time (-0.04 ± 0.01) were of less importance. Respondents were found to be strongly averse (-1.44 ± 0.18) to surgical treatment by a less experienced surgeon and to paying out-of-pocket for their surgical treatment (-0.56 ± 0.05).

CONCLUSION

Our results suggest that patients waiting for TSA to treat severe shoulder OA have minimal willingness to pay for a reduction in wait time or travel time for surgery, yet will pay higher amounts for treatment by an experienced surgeon.

Are patients willing to pay for total shoulder arthroplasty? Evidence from a discrete choice experiment

BACKGROUND

Total shoulder arthroplasty (TSA) is a common treatment to decrease pain and improve shoulder function in patients with severe osteoarthritis (OA). In Canada, patients requiring this procedure often wait a year or more. Our objective was to determine patient preferences related to accessing TSA, specifically comparing out-of-pocket payments for treatment, travel time to hospital, the surgeon's level of experience and wait times.

METHODS

We administered a discrete choice experiment among patients with endstage shoulder OA currently waiting for TSA. Respondents were presented with 14 different choice sets, each with 3 options, and they were asked to choose their preferred scenario. A conditional logit regression model was used to estimate the relative preference and willingness to pay for each attribute.

RESULTS

Sixty-two respondents completed the questionnaire. Three of the 4 attributes significantly influenced treatment preferences. Respondents had a strong preference for an experienced surgeon (mean 0.89 ± standard error [SE] 0.11), while reductions in travel time (-0.07 ± 0.04) or wait time (-0.04 ± 0.01) were of less importance. Respondents were found to be strongly averse (-1.44 ± 0.18) to surgical treatment by a less experienced surgeon and to paying out-of-pocket for their surgical treatment (-0.56 ± 0.05).

CONCLUSION

Our results suggest that patients waiting for TSA to treat severe shoulder OA have minimal willingness to pay for a reduction in wait time or travel time for surgery, yet will pay higher amounts for treatment by an experienced surgeon.

Craniofacial and Dental Defects in the Col1a1Jrt/+ Mouse Model of Osteogenesis Imperfecta

Certain mutations in the COL1A1 and COL1A2 genes produce clinical symptoms of both osteogenesis imperfecta (OI) and Ehlers-Danlos syndrome (EDS) that include abnormal craniofacial growth, dental malocclusion, and dentinogenesis imperfecta. A mouse model (Col1a1(Jrt)/+) was recently developed that had a skeletal phenotype and other features consistent with moderate-to-severe OI and also with EDS. The craniofacial phenotype of 4- and 20-wk-old Col1a1(Jrt)/+ mice and wild-type littermates was assessed by micro-computed tomography (µCT) and morphometry. Teeth and the periodontal ligament compartment were analyzed by µCT, light microscopy/histomorphometry, and electron microscopy. Over time, at 20 wk, Col1a1(Jrt)/+ mice developed smaller heads, a shortened anterior cranial base, class III occlusion, and a mandibular side shift with shorter morphology in the masticatory region (maxilla and mandible). Col1a1(Jrt)/+ mice also had changes in the periodontal compartment and abnormalities in the dentin matrix and mineralization. These findings validate Col1a1(Jrt)/+ mice as a model for OI and EDS in humans.

The treatment of atrophic, recalcitrant long-bone nonunion in the upper extremity with human recombinant bone morphogenetic protein-7 (rhBMP-7) and plate fixation: A retrospective review

INTRODUCTION

Recombinant Human Bone Morphogenetic Protein-7 (rhBMP-7) has been shown to promote fracture healing in both clinical studies and basic science models, however, there is little information from large-scale studies of its use for human nonunion. The purpose of this study was to determine the safety and efficacy of rhBMP-7 in the treatment of atrophic human long-bone nonunions in the upper extremity.

PATIENTS AND METHODS

This was a single center, retrospective, longitudinal cohort study of patients treated with compression plating and the application of rhBMP-7 in isolation to a long-bone nonunion. Patients over sixteen years of age with an atrophic, aseptic nonunion of a humerus, radius, ulna or clavicle were eligible for inclusion.

RESULTS

We identified seventy eligible patients who were treated with rhBMP-7 for a long-bone nonunion between July 1997 and April 2012. The mean age of the patients at the time of treatment with rhBMP-7 was 50.7 years (range, 20-92 years). Five patients were lost to follow-up prior to definitive clinical or radiographic union. During the one-year post-operative period fifty-six patients had achieved union and two patients developed a stable fibrous union after the index procedure. Two patients had early implant failure and five patients had persistent nonunion. Thus, the union rate following initial surgery was 89% (58/65) and four of the five nonunion patients went on to heal following revision open reduction and internal fixation.

CONCLUSION

We found that the application of rhBMP-7 for upper extremity nonunion was an effective method (89% union rate) of treating this challenging pathology. Additionally, if not initially successful, further reconstruction was not compromised by rhBMP-7 use.

Open Reduction and Internal Fixation of Both-Bones Forearm Fractures

Compared with closed reduction or older fixation methods, open reduction and compression plate fixation has dramatically improved the outcomes of displaced diaphyseal forearm fractures. However, the procedure can be technically demanding, with implant choice, surgical approach, accuracy of reduction, and sufficient fracture stability to allow early postoperative motion all having been shown to affect outcome. The procedure is performed with the following steps:The patient is positioned supine on the operating room table with the arm on a hand-table and a tourniquet applied to the upper arm.After skin preparation and draping, a longitudinal incision is made over the volar aspect of the forearm between the flexor carpi radialis tendon and the radial artery, centered over the radial fracture site.The interval between the flexor carpi radialis and the radial artery is developed, and, depending on the location, the deeper musculature is reflected from the bone adjacent to the fracture site, which is debrided of hematoma, irrigated, and cleaned.The fracture is reduced and is provisionally fixed with a Kirschner wire, or lag screw if possible. A small-fragment compression plate that provides at least three bicortical screws proximal and distal to the fracture is selected and is applied with one screw each proximally and distally.After provisional fixation of the radius, a similar process is carried out for the ulna, with use of an approach along the subcutaneous border between the flexor carpi ulnaris and extensor carpi ulnaris. Then the forearm is carefully examined clinically and radiographically to ensure accurate reduction of the fractures and motion/stability of the elbow and wrist.The remainder of the screws are inserted, the fascia of the forearm is not closed, and a standard closure of subcutaneous tissue and skin is performed.Open fractures of the forearm can typically be treated with irrigation, debridement, and immediate fixation. A volar approach is preferred over a dorsal approach for most radial fractures to minimize the risk to the posterior interosseous nerve. Anatomic reduction, especially restoration of the radial bow, is critical for restoration of motion and function. Bone-grafting is rarely indicated, even in comminuted fractures. A rapid return to function, union rates of ≥95%, restoration of forearm strength and stability, and low complication rates have been reported in multiple studies of this technique.

Precontoured plate fixation with interfragmentary lag screw use in a middle third clavicle fracture fixation

Middle third clavicle fractures are common injuries that need surgical fixation in a certain subset of patients. The use of pre-contoured clavicle plates facilitates intra-operative fixation and can reduce soft tissue irritation and hardware removal rates. Lag screw fixation is a well-established technique for the treatment of oblique fractures. Empirical application of this method in clavicle fracture fixation and clavicle non-union treatment has been reported previously. A recent biomechanical study supports the use of a lag screw technique in clavicle fracture fixation when possible. We report a 46 year old patient with a mid-shaft right clavicle fracture who was treated with this technique, which resulted in an excellent clinical outcome.

Atypical Femoral Fracture Despite Prophylactic Intramedullary Nailing: A Case Report

CASE

A forty-three-year-old woman on bisphosphonate therapy sustained an atypical femoral fracture that was successfully treated with an intramedullary nail. After she developed radiographic and clinical signs of an impending stress fracture of the contralateral femur, prophylactic nailing was performed. However, seven months postoperatively, she sustained a spontaneous, complete fracture of the prophylactically nailed femur at the site of the lateral cortical stress lesion.

CONCLUSION

To our knowledge, progression of a bisphosphonate-associated stress lesion to a complete fracture months after initially successful prophylactic intramedullary nailing has not been previously reported. Implications regarding treatment and prognosis are discussed.

Reliability, validity, and responsiveness of the Western Ontario and McMaster Universities Osteoarthritis Index for elderly patients with a femoral neck fracture

BACKGROUND

The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) has been extensively evaluated in groups of patients with osteoarthritis, yet not in patients with a femoral neck fracture. This study aimed to determine the reliability, construct validity, and responsiveness of the WOMAC compared with the Short Form-12 (SF-12) and the EuroQol 5D (EQ-5D) questionnaires for the assessment of elderly patients with a femoral neck fracture.

METHODS

Reliability was tested by assessing the Cronbach alpha. Construct validity was determined with the Pearson correlation coefficient. Change scores were calculated from ten weeks to twelve months of follow-up. Standardized response means and floor and ceiling effects were determined. Analyses were performed to compare the results for patients less than eighty years old with those for patients eighty years of age or older.

RESULTS

The mean WOMAC total score was 89 points before the fracture in the younger patients and increased from 70 points at ten weeks to 81 points at two years postoperatively. In the older age group, these scores were 86, 75, and 78 points. The mean WOMAC pain scores before the fracture and at ten weeks and two years postoperatively were 92, 76, and 87 points, respectively, in the younger age group and 92, 84, and 93 points in the older age group. Function scores were 89, 68, and 79 points for the younger age group and 84, 71, and 73 points for the older age group. The Cronbach alpha for pain, stiffness, function, and the total scale ranged from 0.83 to 0.98 for the younger age group and from 0.79 to 0.97 for the older age group. Construct validity was good, with 82% and 79% of predefined hypotheses confirmed in the younger and older age groups, respectively. Responsiveness was moderate. No floor effects were found. Moderate to large ceiling effects were found for pain and stiffness scales at ten weeks and twelve months in younger patients (18% to 36%) and in the older age group (38% to 53%).

CONCLUSIONS

The WOMAC showed good reliability, construct validity, and responsiveness in both age groups of elderly patients with a femoral neck fracture who had been physically and mentally fit before the fracture. The instrument is suitable for use in future clinical studies in these populations.

CLINICAL RELEVANCE

The results are based on two clinical trials. The questionnaires used concern pure, clinically relevant issues (ability to walk, climb stairs, etc.). Moreover, the results can be used for future research comparing clinical outcomes (or treatments) for populations with a femoral neck fracture.

Extracellular matrix mineralization in murine MC3T3-E1 osteoblast cultures: an ultrastructural, compositional and comparative analysis with mouse bone

Bone cell culture systems are essential tools for the study of the molecular mechanisms regulating extracellular matrix mineralization. MC3T3-E1 osteoblast cell cultures are the most commonly used in vitro model of bone matrix mineralization. Despite the widespread use of this cell line to study biomineralization, there is as yet no systematic characterization of the mineral phase produced in these cultures. Here we provide a comprehensive, multi-technique biophysical characterization of this cell culture mineral and extracellular matrix, and compare it to mouse bone and synthetic apatite mineral standards, to determine the suitability of MC3T3-E1 cultures for biomineralization studies. Elemental compositional analysis by energy-dispersive X-ray spectroscopy (EDS) showed calcium and phosphorus, and trace amounts of sodium and magnesium, in both biological samples. X-ray diffraction (XRD) on resin-embedded intact cultures demonstrated that similar to 1-month-old mouse bone, apatite crystals grew with preferential orientations along the (100), (101) and (111) mineral planes indicative of guided biogenic growth as opposed to dystrophic calcification. XRD of crystals isolated from the cultures revealed that the mineral phase was poorly crystalline hydroxyapatite with 10 to 20nm-sized nanocrystallites. Consistent with the XRD observations, electron diffraction patterns indicated that culture mineral had low crystallinity typical of biological apatites. Fourier-transform infrared spectroscopy (FTIR) confirmed apatitic carbonate and phosphate within the biological samples. With all techniques utilized, cell culture mineral and mouse bone mineral were remarkably similar. Scanning (SEM) and transmission (TEM) electron microscopy showed that the cultures had a dense fibrillar collagen matrix with small, 100nm-sized, collagen fibril-associated mineralization foci which coalesced to form larger mineral aggregates, and where mineralized sites showed the accumulation of the mineral-binding protein osteopontin. Light microscopy, confocal microscopy and three-dimensional reconstructions showed that some cells had dendritic processes and became embedded within the mineral in an osteocyte-like manner. In conclusion, we have documented characteristics of the mineral and matrix phases of MC3T3-E1 osteoblast cultures, and have determined that the structural and compositional properties of the mineral are highly similar to that of mouse bone.

Geriatric trauma: the role of immediate arthroplasty

Periarticular fractures in elderly patients are challenging to manage because the fractures are typically comminuted and the bone is osteopenic, which often result in the failure of internal fixation. Patients who sustain these fractures demand immediate mobilization or they often do not recover their preinjury level of function. In geriatric patients, immediate arthroplasty provides an alternative to internal fixation for many periarticular fractures of the shoulder, elbow, and hip.

Compounded PHOSPHO1/ALPL deficiencies reduce dentin mineralization

Phosphatases are involved in bone and tooth mineralization, but their mechanisms of action are not completely understood. Tissue-nonspecific alkaline phosphatase (TNAP, ALPL) regulates inhibitory extracellular pyrophosphate through its pyrophosphatase activity to control mineral propagation in the matrix; mice without TNAP lack acellular cementum, and have mineralization defects in dentin, enamel, and bone. PHOSPHO1 is a phosphatase found within membrane-bounded matrix vesicles in mineralized tissues, and double ablation of Alpl and Phospho1 in mice leads to a complete absence of skeletal mineralization. Here, we describe mineralization abnormalities in the teeth of Phospho1(-/-) mice, and in compound knockout mice lacking Phospho1 and one allele of Alpl (Phospho1(-/-);Alpl(+/-) ). In wild-type mice, PHOSPHO1 and TNAP co-localized to odontoblasts at early stages of dentinogenesis, coincident with the early mineralization of mantle dentin. In Phospho1 knockout mice, radiography, micro-computed tomography, histology, and transmission electron microscopy all demonstrated mineralization abnormalities of incisor dentin, with the most remarkable findings being reduced overall mineralization coincident with decreased matrix vesicle mineralization in the Phospho1(-/-) mice, and the almost complete absence of matrix vesicles in the Phospho1(-/-);Alpl(+/-) mice, whose incisors showed a further reduction in mineralization. Results from this study support prominent non-redundant roles for both PHOSPHO1 and TNAP in dentin mineralization.

Latissimus dorsi tendon transfer for irreparable tears of the rotator cuff: An anatomical study to assess the neurovascular hazards and ways of improving tendon excursion

Latissimus dorsi tendon transfer (LDTT) is technically challenging. In order to clarify the local structural anatomy, we undertook a morphometric study using six complete cadavers (12 shoulders). Measurements were made from the tendon to the nearby neurovascular structures with the arm in two positions: flexed and internally rotated, and adducted in neutral rotation. The tendon was then transferred and measurements were taken from the edge of the tendon to a reference point on the humeral head in order to assess the effect of a novel two-stage release on the excursion of the tendon. With the shoulder flexed and internally rotated, the mean distances between the superior tendon edge and the radial nerve, brachial artery, axillary nerve and posterior circumflex artery were 30 mm (26 to 34), 28 mm (17 to 39), 21 mm (12 to 28) and 15 mm (10 to 21), respectively. The mean distance between the inferior tendon edge and the radial nerve, brachial artery and profunda brachii artery was 18 mm (8 to 27), 22 mm (15 to 32) and 14 mm (7 to 21), respectively. Moving the arm to a neutral position reduced these distances. A mean of 15 mm (8 to 21) was gained from a standard soft-tissue release, and 32 mm (20 to 45) from an extensile release. These figures help to define further the structural anatomy of this region and the potential for transfer of the latissimus dorsi tendon.

Mineralization of dense collagen hydrogel scaffolds by human pulp cells

While advances in biomineralization have been made in recent years, unanswered questions persist on bone- and tooth-cell differentiation, on outside-in signaling from the extracellular matrix, and on the link between protein expression and mineral deposition. In the present study, we validate the use of a bioengineered three-dimensional (3D) dense collagen hydrogel scaffold as a cell-culture model to explore these questions. Dental pulp progenitor/stem cells from human exfoliated deciduous teeth (SHEDs) were seeded into an extracellular matrix-like collagen gel whose fibrillar density was increased through plastic compression. SHED viability, morphology, and metabolic activity, as well as scaffold mineralization, were investigated over 24 days in culture. Additionally, measurements of alkaline phosphatase enzymatic activity, together with immunoblotting for mineralized tissue cell markers ALPL (tissue-non-specific alkaline phosphatase), DMP1 (dentin matrix protein 1), and OPN (osteopontin), demonstrated osteo/odontogenic cell differentiation in the dense collagen scaffolds coincident with mineralization. Analyses of the mineral phase by electron microscopy, including electron diffraction and energy-dispersive x-ray spectroscopy, combined with Fourier-transform infrared spectroscopy and biochemical analyses, were consistent with the formation of apatitic mineral that was frequently aligned along collagen fibrils. In conclusion, use of a 3D dense collagen scaffold promoted SHED osteo/odontogenic cell differentiation and mineralization.

Tooth root dentin mineralization defects in a mouse model of hypophosphatasia

Tissue-nonspecific alkaline phosphatase (TNAP) is expressed in mineralizing tissues and functions to reduce pyrophosphate (PP(i) ), a potent inhibitor of mineralization. Loss of TNAP function causes hypophosphatasia (HPP), a heritable disorder marked by increased PP(i) , resulting in rickets and osteomalacia. Tooth root cementum defects are well described in both HPP patients and in Alpl(-/-) mice, a model for infantile HPP. In Alpl(-/-) mice, dentin mineralization is specifically delayed in the root; however, reports from human HPP patients are variable and inconsistent regarding dentin defects. In the current study, we aimed to define the molecular basis for changes in dentinogenesis observed in Alpl(-/-) mice. TNAP was found to be highly expressed by mature odontoblasts, and Alpl(-/-) molar and incisor roots featured defective dentin mineralization, ranging from a mild delay to severely disturbed root dentinogenesis. Lack of mantle dentin mineralization was associated with disordered and dysmorphic odontoblasts having disrupted expression of marker genes osteocalcin and dentin sialophosphoprotein. The formation of, initiation of mineralization within, and rupture of matrix vesicles in Alpl(-/-) dentin matrix was not affected. Osteopontin (OPN), an inhibitor of mineralization that contributes to the skeletal pathology in Alpl(-/-) mice, was present in the generally unmineralized Alpl(-/-) mantle dentin at ruptured mineralizing matrix vesicles, as detected by immunohistochemistry and by immunogold labeling. However, ablating the OPN-encoding Spp1 gene in Alpl(-/-) mice was insufficient to rescue the dentin mineralization defect. Administration of bioengineered mineral-targeting human TNAP (ENB-0040) to Alpl(-/-) mice corrected defective dentin mineralization in the molar roots. These studies reveal that TNAP participates in root dentin formation and confirm that reduction of PP(i) during dentinogenesis is necessary for odontoblast differentiation, dentin matrix secretion, and mineralization. Furthermore, these results elucidate developmental mechanisms underlying dentin pathology in HPP patients, and begin to explain the reported variability in the dentin/pulp complex pathology in these patients.