JAAOS

JAAOS, Volume 25, No. 2


Ankle Distraction Arthroplasty: Indications, Technique, and Outcomes

Ankle distraction is an alternative to ankle arthrodesis or total ankle arthroplasty in younger patients with arthritis. Ankle distraction involves the use of external fixation to mechanically unload the ankle joint, which allows for stable, congruent range of motion in the setting of decreased mechanical loading, potentially promoting cartilage repair. Adjunct surgical procedures are frequently done to address lower-extremity malalignment, ankle equinus contractures, and impinging tibiotalar osteophytes. Patients can bear full weight during the treatment course. The distraction frame frequently uses a hinge, and patients are encouraged to do daily range-of-motion exercises. Although the initial goal of the procedure is to delay arthrodesis, many patients achieve lasting clinical benefits, obviating the need for total ankle arthroplasty or fusion. Complications associated with external fixation are common, and patients should be counseled that clinical improvements occur slowly and often are not achieved until at least 1 year after frame removal.

      • Subspecialty:
      • Ankle

      • Foot and Ankle

    Complex Distal Radius Fractures: An Anatomic Algorithm for Surgical Management

    Most distal radius fractures result from low-energy mechanisms and can be successfully treated nonsurgically or with a variety of surgical techniques if indicated. High-energy distal radius fractures can involve extensive comminution or bone loss with concomitant ligament, soft-tissue, and neurovascular injuries. In patients with complex distal radius fractures, reconstruction of the distal radius, ulna, and triangular fibrocartilage complex can be challenging. Effective restoration of the bony architecture requires intimate knowledge of the anatomy of the distal radius, a thorough understanding of the goals of treatment, versatility in surgical approaches, and familiarity with multiple fixation options.

        • Subspecialty:
        • Hand

        • Wrist

      Current Trends in Ulnar Collateral Ligament Reconstruction Surgery Among Newly Trained Orthopaedic Surgeons

      Introduction: Ulnar collateral ligament (UCL) reconstructions are being performed with an increasing annual incidence. The purpose of this study was to evaluate trends in UCL surgery among recently trained orthopaedic surgeons.

      Methods: The American Board of Orthopaedic Surgeons (ABOS) database was used to identify all UCL reconstructions from 2004 to 2013. Procedures were identified by Current Procedural Terminology (CPT) codes and verified by International Classification of Disease, Ninth Revision (ICD-9) codes. Data on surgeon fellowship, practice location, concomitant surgical procedures, and complications were collected.

      Results: One hundred sixty-four UCL reconstructions were performed by 133 ABOS Part II candidates. The annual incidence increased from 1.52 to 3.46 cases per 10,000 (P = 0.042). Reconstructions were most commonly performed by surgeons with fellowship training in sports medicine (65.9%), hand and upper extremity (18.9%), and shoulder and elbow (9.1%). Most reconstructions were performed in isolation (57.3%), or with ulnar nerve transposition (32.9%) or elbow arthroscopy (9.8%). Concomitant elbow arthroscopy rates decreased significantly (P = 0.022). Complications occurred in 9.8% of cases, although the rates did not significantly change (P = 0.466).

      Conclusions: UCL reconstructions are being performed with increasing frequency. Concomitant procedure rates remained the same, although arthroscopy was less commonly performed. Complication rates did not change considerably over the observed period. Further study of the surgical trends and associated long-term outcomes is warranted. Level of Evidence: Level IV

          • Subspecialty:
          • Elbow

          • Shoulder and Elbow

          • Adult Reconstruction

          • Surgery and Treatment

        Descriptive Epidemiology of Acetabular Dysplasia: The Academic Network of Conservational Hip Outcomes Research (ANCHOR) Periacetabular Osteotomy

        Background: Periacetabular osteotomy (PAO) is an established treatment for symptomatic acetabular dysplasia, which is a well-recognized cause of hip pain, functional limitations, and secondary osteoarthritis. The purpose of this study was to describe the demographics of patients undergoing PAO, the baseline patient-reported outcome measures for this population, and the types of adjunctive procedures performed at the time of PAO surgery.

        Methods: Demographics, disease characteristics, and patient-reported functional measures were prospectively collected from all patients who underwent PAO performed by 12 surgeons from 2008 to 2013.

        Results: We enrolled 950 consecutive patients (982 hips) in the study; 83% were female and 17% were male, with an average age of 25.3 years and an average body mass index (BMI) of 24.6 kg/m2. Most patients were Caucasian (87%), and 15% had undergone previous hip surgery. Before PAO was performed, most patients had had symptoms for 1 to 3 years. Baseline modified Harris Hip and University of California Los Angeles activity scores (61.8 and 6.6, respectively) indicated that patients had considerable functional limitations.

        Discussion: Patients undergoing PAO for symptomatic dysplasia were predominantly young, female, and Caucasian with a normal BMI. Many patients had undergone prior hip surgery, and most had had symptoms for several years before treatment. Baseline patient-reported functional scores demonstrated marked functional limitations. Adjunctive procedures for intra-articular pathology, especially femoral osteochondroplasty and hip arthroscopy, are commonly performed at the time of PAO.

            • Subspecialty:
            • Hip

          Differentiating Hip Pathology From Lumbar Spine Pathology: Key Points of Evaluation and Management

          The diagnosis and treatment of patients who have both hip and lumbar spine pathologies may be a challenge because overlapping symptoms may delay a correct diagnosis and appropriate treatment. Common complaints of patients who have both hip and lumbar spine pathologies include low back pain with associated buttock, groin, thigh, and, possibly, knee pain. A thorough patient history should be obtained and a complete physical examination should be performed in these patients to identify the primary source of pain. Plain and advanced imaging studies and diagnostic injections can be used to further delineate the primary pathology and guide the appropriate sequence of treatment. Both the surgeon and the patient should understand that, although one pathology is managed, the management of the other pathology may be necessary because of persistent pain. The recognition of both entities may help reduce the likelihood of misdiagnosis, and the management of both entities in the appropriate sequence may help reduce the likelihood of persistent symptoms.

              • Subspecialty:
              • Diseases and Conditions

              • Spine

              • Spine

              • Hip

            Heterotopic Ossification in Acetabular Fracture Surgery

            Heterotopic ossification (HO) is a common complication of the surgical treatment of acetabular fractures. HO is the formation of trabecular bone in soft tissues where bone does not usually occur. Over the last decade, many risk factors have been identified for HO after surgical fixation of acetabular fractures; however, prophylaxis and treatment of this condition are controversial. Potential preventive measures range from NSAIDs to external beam irradiation, but recent studies have questioned the utility of these measures. The Brooker classification system, which has been correlated with patient function and outcomes, is most commonly used to describe HO severity. Advances will assist in the diagnosis, prevention, and management of HO as well as the assessment of risk factors that could affect outcomes.

                • Subspecialty:
                • Hip

                • Pelvis

              Joint Contractures Resulting From Prolonged Immobilization: Etiology, Prevention, and Management

              Patients who are immobilized for a prolonged period are at risk for developing joint contractures, which often affect functional outcomes. Nonsurgical interventions are useful for preventing joint contractures. However, once contractures develop, these interventions frequently fail to restore function over the long term. To increase the rehabilitation potential of an extremity with refractory function-limiting contractures, surgery is often required.

                  • Subspecialty:
                  • Joints

                Spinal Realignment for Adult Deformity: Three-column Osteotomies Alter Total Hip Acetabular Component Positioning

                Introduction: A goal of adult spinal deformity surgery is correction of sagittal imbalance by increasing lumbar lordosis (LL), allowing a previously retroverted pelvis to normalize as evidenced by decreases in pelvic tilt (PT). Realignment of pelvic orientation may alter the position of preexisting total hip arthroplasties (THAs).

                Methods: Twenty-seven patients with unilateral THA who underwent thoracolumbar fusions for adult spinal deformity from the pelvis to L1 or above were retrospectively reviewed (levels fused, 10.3 [range, 6 to 17]; age, 70 ± 9 years). Comparisons of preoperative and postoperative spinal deformity parameters, acetabular tilt (AT), and acetabular cup abduction angle (CAA) were performed, with subgroup analysis for those who had undergone three-column osteotomy and those who had not.

                Results: Preoperative deformity was severe, with findings of a sagittal vertical axis >9 cm, PT >25°, and pelvic incidence-LL >20°. Postoperatively, AT decreased significantly (−7° ± 10°; P < 0.001), signifying relative acetabular retroversion. Comparing patients with three-column osteotomy versus those without, AT changes were greater in those with three-column osteotomy (11° ± 7° and −2 ± 10°, respectively; P = 0.024). AT was significantly correlated with changes of PT (r = 0.704; P < 0.001) and LL (r = −0.481; P = 0.011). AT decreased (ie, retroverted) 1° for every 3.23° of LL or 1.13° of PT correction. The coronal plane CAA did not change substantially.

                Discussion: Spinal deformity correction, with techniques such as three-column osteotomy, result in significant THA acetabular component repositioning in the sagittal plane. Resultant decreased AT (ie, retroversion) theoretically may affect tribology, wear, and joint stability and warrants further investigation.

                    • Subspecialty:
                    • Treatments and Surgery

                    • Spine

                    • Spine

                    • Hip

                  The Effect of Cervical Interbody Cage Morphology, Material Composition, and Substrate Density on Cage Subsidence

                  Background: Interbody cages used in spinal fusion surgery can subside into the adjacent vertebral bodies after implantation, leading to loss of spinal height, malalignment, and possible radicular symptoms. Several factors may contribute to cage subsidence.

                  Methods: This in vitro investigation examined the possible contribution of substrate density, cage contact area (ie, cage footprint), cage filling, cage end plate surface texture, and cage material composition on the magnitude of subsidence. Commercially available cervical interbody cages of two sizes (16 × 12 mm and 17 × 14 mm) were implanted between foam blocks of two different densities and were cyclically loaded. Cages were made of titanium alloy (Ti4Al6V), silicon nitride ceramic (Si3N4), or polyether ether ketone (n = 8 cages of each material type). Additional testing was performed on Si3N4 cages of the smaller size with nontextured surfaces and with filled cores.

                  Results: Subsidence measurements showed that lower foam density had the greatest influence on subsidence, followed by smaller cage footprint. Cage material had no effect on subsidence. In the additional testing of small-footprint Si3N4 cages, the cages in which the core was filled with a load-bearing porous material had less subsidence in lower-density foam than the cages with an empty core had, whereas cage end plate surface texture had no effect on subsidence.

                  Conclusion: Ranking of the relative impact of these factors indicated that substrate density had the greatest contribution to the measured subsidence (approximately 1.7 times and approximately 67 times greater than the contributions of cage footprint area and material, respectively). The contribution of cage footprint area to subsidence was found to be 40 times greater than the contribution of cage material to subsidence.

                      • Subspecialty:
                      • Spine

                      • Spine

                    The Spine in Patients With Osteogenesis Imperfecta

                    Osteogenesis imperfecta is a genetic disorder of type I collagen. Although multiple genotypes and phenotypes are associated with osteogenesis imperfecta, approximately 90% of the mutations are in the COL1A1 and COL1A2 genes. Osteogenesis imperfecta is characterized by bone fragility. Patients typically have multiple fractures or limb deformity; however, the spine can also be affected. Spinal manifestations include scoliosis, kyphosis, craniocervical junction abnormalities, and lumbosacral pathology. The incidence of lumbosacral spondylolysis and spondylolisthesis is higher in patients with osteogenesis imperfecta than in the general population. Use of diphosphonates has been found to decrease the rate of progression of scoliosis in patients with osteogenesis imperfecta. A lateral cervical radiograph is recommended in patients with this condition before age 6 years for surveillance of craniocervical junction abnormalities, such as basilar impression. Intraoperative and anesthetic considerations in patients with osteogenesis imperfecta include challenges related to fracture risk, airway management, pulmonary function, and blood loss.

                        • Subspecialty:
                        • Spine

                        • Spine

                      Trunnion Corrosion in Metal-on-Polyethylene Total Hip Arthroplasty: A Case Series

                      Introduction: Modular total hip arthroplasty implants can help the operating surgeon reproduce the optimum limb length and offset; however, the modularity can lead to fretting and corrosion with associated metal-related problems. Although metal-on-metal bearings are often reported to have problems, recent case reports suggest that the problems can occur with any articulation, usually as a result of problems at the head/neck junction.

                      Methods: We retrospectively reviewed three cases of a specific implant combination with nontraumatic trunnion failure, with two cases presenting as acute complete dissociation of the femoral head from the neck.

                      Results: All three cases had failure of the Accolade TMZF plus stem and trunnion (Stryker) that progressed rapidly from the onset of symptoms. The most likely contributing factors to failure were large femoral head size, high horizontal offset, a low angled neck, and a β titanium alloy taper with a cobalt-chromium head.

                      Conclusion: We recommend regular follow-up of all patients with Accolade TMZF stems, and patients should be advised to seek immediate medical attention if they have any new mechanical symptoms in a metal-on-polyethylene total hip arthroplasty. Providers should specifically look for any alteration of alignment between the femoral head and neck in follow-up radiographs.

                          • Subspecialty:
                          • Hip

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