JAAOS, Volume 25, No. 9

Posterior Glenohumeral Instability: Evidence-based Treatment

Posterior glenohumeral instability is an increasingly important clinical finding in athletic patients. Over the last decade, basic and clinical research has improved our understanding of the pathoanatomy and biomechanics of this challenging disorder, as well as our ability to diagnose and appropriately treat it. Although recurrent posterior shoulder instability is not as common as anterior instability, it is prevalent among specific populations, including football and rugby players, and may be overlooked by clinicians who are unaware of the typical physical examination and radiographic findings.

      Revision Total Knee Arthroplasty for the Management of Periprosthetic Fractures

      Periprosthetic fractures after total knee arthroplasty (TKA) can present reconstructive challenges. Not only is the procedure technically complex, but patients with these fractures may have multiple comorbidities, making them prone to postoperative complications. Early mobilization is particularly beneficial in patients with multiple comorbidities. Certain patient factors and fracture types may make revision TKA the ideal management option. Periprosthetic fractures around the knee implant occur most frequently in the distal femur, followed by the tibia and the patella. Risk factors typically are grouped into patient factors (eg, osteoporosis, obesity) and surgical factors (eg, anterior notching, implant malposition). Surgical options for periprosthetic fractures that involve the distal femur or proximal tibia include reconstruction of the bone stock with augments or metal cones or replacement with an endoprosthesis.

          • Subspecialty:
          • Knee

        Management of Lower Extremity Long-bone Fractures in Spinal Cord Injury Patients

        The AO classification system, used as a guide for modern fracture care and fixation, follows a basic philosophy of care that emphasizes early mobility and return to function. Lower extremity long-bone fractures in patients with spinal cord injury often are pathologic injuries that present unique challenges, to which the AO principles may not be entirely applicable. Optimal treatment achieves healing without affecting the functional level of the patient. These injuries often result from low-energy mechanisms in nonambulatory patients with osteopenic bone and a thin, insensate soft-tissue envelope. The complication rate can be high, and the outcomes can be catastrophic without proper care. Satisfactory results can be obtained through various methods of immobilization. Less frequently, internal fixation is applied. In certain cases, after discussion with the patient, amputation may be suitable. Prevention strategies aim to minimize bone loss and muscle atrophy.

            Normal Palmar Anatomy and Variations That Impact Median Nerve Decompression

            Annually, carpal tunnel release is one of the most commonly executed orthopaedic procedures. Despite the frequency of the procedure, complications may occur as a result of anatomic variations. Understanding both normal and variant anatomy, including anomalies in neural, vascular, tendinous, and muscular structures about the carpal tunnel, is fundamental to achieving both safe and efficacious surgery. Reviewing and aggregating this information reveals certain principles that may lead to the safest possible surgical approach. Although it is likely that no true internervous plane or so-called safe zone exists during the approach for carpal tunnel release, the long-ring web space axis does appear to pose the lowest risk to important structures.

                Marfan Syndrome: A Clinical Update

                Marfan syndrome is a connective tissue disorder that can affect many organ systems. Affected patients present with orthopaedic manifestations of the syndrome during all phases of life. Pain caused by musculoskeletal abnormalities often requires definitive orthopaedic treatment. Orthopaedic surgeons must understand the phenotypes of Marfan syndrome so they can recognize when screening is warranted and can appropriately address the skeletal manifestations. Through medical advancements, patients with Marfan syndrome are living longer and more active lives. Knowledge of the latest diagnostic criteria for the disorder, as well as of advances in understanding the skeletal phenotype, clinical trials of medication therapy, and lifestyle considerations is important for orthopaedic surgeons who treat these patients because these clinicians often are the first to suspect Marfan syndrome and recommend screening.

                    The Crankshaft Phenomenon

                    The crankshaft phenomenon, a progressive rotational and angular spinal deformity that can occur after posterior spinal surgery, has been reported in pediatric patients with idiopathic, congenital, and neuromuscular scoliosis. In the skeletally immature patient, the crankshaft phenomenon is thought to occur secondary to continued growth of the anterior elements of the spine after solid posterior spinal fusion. The condition has also been reported in the setting of newer, so-called growth-friendly posterior distraction-based spinal instrumentation. The clinical evidence of crankshaft phenomenon is often subtle, whereas radiographic findings are usually more apparent. However, objective measurement of radiographic signs may be complicated by instrumentation and postoperative changes. Treatment options for patients with the crankshaft phenomenon are limited; in those with problematic deformity and/or risk of progression, additional surgery may be indicated.

                        Temporal Healing of Achilles Tendons After Injury in Rodents Depends on Surgical Treatment and Activity

                        Introduction: Achilles tendon ruptures affect 15 of 100,000 women and 55 of 100,000 men each year. Controversy continues to exist regarding optimal treatment and rehabilitation protocols. The objective of this study was to investigate the temporal effects of surgical repair and immobilization or activity on Achilles tendon healing and limb function after complete transection in rodents.

                        Methods: Injured tendons were repaired (n = 64) or left nonrepaired (n = 64). The animals in both cohorts were further randomized into groups immobilized in plantar flexion for 1, 3, or 6 weeks that later resumed cage and treadmill activity for 5, 3, or 0 weeks, respectively (n = 36 for each regimen), which were euthanized at 6 weeks after injury, or into groups immobilized for 1 week and then euthanized (n = 20).

                        Results: At 6 weeks after injury, the groups that had 1 week of immobilization and 5 weeks of activity had increased range of motion and decreased ankle joint toe stiffness compared with the groups that had 3 weeks of immobilization and 3 weeks of activity. The groups with 6 weeks of immobilization and no activity period had decreased tendon cross-sectional area but increased tendon echogenicity and collagen alignment. Surgical treatment dramatically decreased fatigue cycles to failure in repaired tendons from groups with 1 week of immobilization and 5 weeks of activity. Normalized comparisons between 1-week and 6-week postinjury data demonstrated that changes in tendon healing properties (area, alignment, and echogenicity) were maximized by 1 week of immobilization and 5 weeks of activity, compared with 6 weeks of immobilization and no activity period.

                        Discussion: This study builds on an earlier study of Achilles tendon fatigue mechanics and functional outcomes during early healing by examining the temporal effects of different immobilization and/or activity regimens after initial postinjury immobilization.

                        Conclusion: This study demonstrates how the temporal postinjury healing response of rodent Achilles tendons depends on both surgical treatment and the timing of immobilization/activity timing. The different pattern of healing and qualities of repaired and nonrepaired tendons suggest that two very different healing processes may occur, depending on the chosen immobilization/activity regimen.

                            Early Lessons on Bundled Payment at an Academic Medical Center

                            Introduction: Orthopaedic care is shifting to alternative payment models. We examined whether New York University Langone Medical Center achieved savings under the Centers for Medicare and Medicaid Services Bundled Payments for Care Improvement initiative.

                            Methods: This study was a difference-in-differences study of Medicare fee-for-service patients hospitalized from April 2011 to June 2012 and October 2013 to December 2014 for lower extremity joint arthroplasty, cardiac valve procedures, or spine surgery (intervention groups), or for congestive heart failure, major bowel procedures, medical peripheral vascular disorders, medical noninfectious orthopaedic care, or stroke (control group). We examined total episode costs and costs by service category.

                            Results: We included 2,940 intervention episodes and 1,474 control episodes. Relative to the trend in the control group, lower extremity joint arthroplasty episodes achieved the greatest savings: adjusted average episode cost during the intervention period decreased by $3,017 (95% confidence interval [CI], −$6,066 to $31). For cardiac procedures, the adjusted average episode cost decreased by $2,999 (95% CI, −$8,103 to $2,105), and for spinal fusion, it increased by $8,291 (95% CI, $2,879 to $13,703). Savings were driven predominantly by shifting postdischarge care from inpatient rehabilitation facilities to home. Spinal fusion index admission costs increased because of changes in surgical technique.

                            Discussion: Under bundled payment, New York University Langone Medical Center decreased total episode costs in patients undergoing lower extremity joint arthroplasty. For patients undergoing cardiac valve procedures, evidence of savings was not as strong, and for patients undergoing spinal fusion, total episode costs increased. For all three conditions, the proportion of patients referred to inpatient rehabilitation facilities upon discharge decreased. These changes were not associated with an increase in index hospital length of stay or readmission rate.

                            Conclusion: Opportunities for savings under bundled payment may be greater for lower extremity joint arthroplasty than for other conditions.

                                Hallux Rigidus Grade Does Not Correlate With Foot and Ankle Ability Measure Score

                                Introduction: Classification systems for hallux rigidus imply that, as radiographic changes progress, symptoms will concurrently increase in severity. However, symptom intensity and radiographic severity can be discordant for many patients. We studied the correlation between hallux rigidus grades and the Foot and Ankle Ability Measure (FAAM) scores to better understand this relationship.

                                Methods: We retrospectively reviewed weight-bearing radiographs of the foot and FAAM Activities of Daily Living (ADL) questionnaires for 84 patients with hallux rigidus. The Spearman rank coefficient was used to correlate clinical-radiographic hallux rigidus grade with FAAM ADL scores.

                                Results: In 84 patients, the clinical-radiographic grade for hallux rigidus showed no relationship with FAAM ADL score (r = −0.10; P = 0.36) but did show moderate correlation with patient age (r = 0.63; P < 0.001).

                                Discussion: Advancing radiographic changes in hallux rigidus did not correspond with patient symptoms as measured via FAAM ADL scores.

                                Conclusion: The reliability and validity of current grading criteria for hallux rigidus may require further exploration.

                                Level of Evidence: Level III

                                    Safe Surgical Dislocation for Femoral Head Fractures

                                    Femoral head fractures are high-energy injuries often associated with posterior hip dislocation. Surgical treatment is recommended in cases of incongruent or unstable hip joint after closed reduction. Safe surgical dislocation has emerged as the approach of choice in these injuries. It provides circumferential exposure of the femoral head and acetabulum to address fractures and labral injuries without additional risk of osteonecrosis of the femoral head. Sound knowledge of the vascular supply to the femoral head, meticulous posterior soft-tissue dissection, and a precise osteotomy technique are imperative to avoid iatrogenic injury to the femoral head blood supply. In this surgical technique video, we explain the anatomic basis, key landmarks, and techniques in performing a safe surgical dislocation for a Pipkin type II fracture-dislocation. Watch the video trailer: http://links.lww.com/JAAOS/A42.

                                        Anatomy Revisited: Medial Longitudinal Foot Arch

                                        Adult-acquired flatfoot deformity is a frequent clinical entity leading to invalidating symptoms in middle-aged patients. In this video, we revisit the anatomy of the static stabilizing structures of the medial longitudinal foot arch. These structures include the plantar fascia; the talocalcaneal interosseous ligament; and the spring ligament complex, consisting of the tibionavicular portion of the superficial deltoid ligament, the superomedial bundle of the calcaneonavicular ligament, and the inferior bundle of the calcaneonavicular ligament. With the help of a gait simulator, we illustrate the effect of sectioning these ligaments. Based on the anatomic characteristics, we suggest a reconstruction technique to repair the spring ligament complex. Watch the video trailer: http://links.lww.com/JAAOS/A43.

                                            Targeted Muscle Reinnervation and its Role in Acute Management of Above-Elbow Amputations

                                            Targeted muscle reinnervation (TMR) is a surgical technique that can provide patients intuitive myoelectric prosthetic control as well as prevention of, or relief from, neuroma-associated pain. This technique involves nerve transfers that increase the number of available surface electromyography (EMG) targets leading to improved patient control of the myoelectric prosthesis. Additionally, utilization of EMG pattern recognition has evolved in conjunction with TMR to further improve prosthetic control. Early case studies seem to indicate that TMR is successful in prevention of early neuroma formation after amputation and is a highly effective surgical intervention for the treatment of painful neuromas. The technique of TMR in the above-elbow amputee has been well described. These advances in surgical and prosthetic technique have led to implementation of TMR in all patients with transhumeral amputations at our facility during the initial hospitalization following their injury as discussed by other institutions. In this video, we discuss technical aspects of TMR in above-elbow amputees as well as the importance of a patient care team including physicians, therapists, and prosthetic designers. We present two patients who underwent TMR after traumatic transhumeral amputation. Both patients underwent surgical intervention shortly after initial injury. In both cases muscle reinnervation occurred, leading to reliable EMG signals for control of a myoelectric prosthesis. The intuitive nature of TMR led to early control of the prosthesis. In both cases, patients were able to control a myoelectric prosthesis with use of reinnervated muscles using pattern recognition–based myoelectric prosthesis and neither has had painful neuroma formation. Watch the video trailer: http://links.lww.com/JAAOS/A44.