William T. Hardaker

Management of Medial-Sided Knee Injuries, Part 1 Medial Collateral Ligament

The medial collateral ligament complex is a primary stabilizer that combines static and dynamic resistance to direct valgus stress while contributing significant restraints to rotatory motion and anterior-posterior translation. Varying opinions exist among investigators regarding injury classification and treatment algorithms. Whereas most agree that the majority of isolated medial collateral ligament complex injuries can be treated nonoperatively, isolated injuries with chronic instability and multiligament injuries may require operative intervention. Substantial confounding factors are present within published reports, making comparative analyses and systematic review challenging. This review focuses on the anatomy and biomechanics of the medial structures of the knee; it discusses the clinical evaluation of complex injuries; and it reviews nonoperative and operative treatment methods.

Knee arthrodesis with circular external fixation.

Knee arthrodesis can enable limb salvage in patients with disability secondary to trauma, infected total knee arthroplasty, pyarthrosis, and other complications. Historically, intramedullary nailing has resulted in the highest overall knee fusion rates. However, intramedullary nailing is relatively contraindicated in the presence of active infection. Nineteen patients who underwent knee arthrodesis with circular external fixation were studied retrospectively. Postoperative radiographs were evaluated for evidence of bony fusion, which was defined as trabecular bridging between the femur and tibia. Patients were interviewed and graded using the functional assessment portion of the Knee Society clinical rating system. Fusion was successful in 13 of 19 (68%) patients. Overall, patients spent an average of 4 months 8 days wearing the circular external fixator. Average time to radiographic and clinical evidence of arthrodesis (defined as lack of motion across the fusion site) was 4 months 18 days. No patient with successful fusion considered himself or herself housebound. All but one of these patients require some form of assistive device for ambulation. Complications occurred in 16 of 19 (84%) patients overall. Superficial pin tract infection (55%) and nonunion (32%) were the most common. Circular external fixation is an effective method for obtaining knee arthrodesis in patients who are not good candidates for intramedullary nailing.

Management of medial-sided knee injuries, part 2: posteromedial corner.

Injury to the posteromedial corner (PMC) of the knee differs anatomically and biomechanically from isolated injury to the medial collateral ligament. Newer anatomic and biomechanical studies are refining the field’s understanding of the medial side of the knee, as well as its role in multiple ligament injuries. Valgus instability places additional strain on a reconstructed anterior or posterior cruciate ligament, which can contribute to late graft failure. Injuries to the PMC may not heal without surgical repair or reconstruction, particularly when part of a multiple-ligament injury. Identification of PMC injury before cruciate reconstruction is important so that appropriate repair or reconstruction of the PMC and medial collateral ligament can be undertaken at the same time. This article reviews the relevant literature on the PMC, discusses reasons for selective operative management, and illustrates reconstructive strategies for PMC injuries occurring as part of a medial-sided or multiligament injury to the knee.

Bilateral transpedicular decompression and Harrington rod stabilization in the management of severe thoracolumbar burst fractures.

Fifty–eight patients with severe thoracolumbar burst fractures were treated with bilateral transpedicular decompression, Harrington rod instrumentation, and spine fusion. Spinal realignment and stabilization was achieved by contoured dual Harrington distraction rods supplemented by segmental sublaminal wiring. Posterior element fractures were noted in 25 patients, 9 of whom had associated dural tears. Computed tomography was performed to assess the cross–sectional area of the spinal canal before surgery and after decompression. Patients at initial evaluation averaged greater than 67% spinal canal compromise. After surgery, successful decompression was accomplished in 57 patients. One patient required staged, anterior thoracoabdominal decompression and fibula strut grafting. At follow–up (average, 43 months; range, 25–70 months), neurologic improvement was found in 77% of the patients who initially presented with neurologic deficits. Thirty–four of 40 patients with incomplete paraplegia improved one or more subgroups on the Frankel scale. A solid fusion was attained in all 58 patients. No patient had a significant residual kyphotic deformity. Single–stage bilateral transpedicular decompression and dual Harrington rod instrumentation reliably provides decompression of the spinal canal and restores spinal alignment. The procedure allows early mobilization and provides an environment for solid fusion and maximum neurologic return.

Redistribution of Renal Intracortical Blood Flow during Dopamine Infusion in Dogs

We determined the effect of intravenous and renal intra-arterial infusion of dopamine on the distribution of intracortical blood flow in kidneys of anesthetized dogs. Total renal and renal intracortical blood flows in dogs receiving dopamine intravenously were quantified by the radioactive microsphere technique with reference sampling. In dogs receiving dopamine by renal intra-arterial infusion, total renal and renal intracortical blood flows were determined from radioactive microsphere and electromagnetic flowmeter data. Tissue perfusion rates for the total kidney, the renal cortex, the renal outer cortex, and the renal inner cortex increased following either intravenous or direct renal intra-arterial infusion of dopamine. Dopamine infusion by either method caused a relative redistribution of renal blood flow from the outer twothirds to the inner one-third of the renal cortex. During direct dopamine infusion into the renal artery, no significant changes in renal hemodynamics occurred in the contralateral kidney. No changes in arterial blood pressure occurred during dopamine infusion by either method. These observations imply that the change in the fractional distribution of renal intracortical blood flow following dopamine infusion is not dependent on a systemic mode of action. This pattern of flow redistribution suggests that the intrarenal dopamine-specific receptor may be in higher number in the inner cortex or that the redistribution of cortical flow after dopamine infusion may reflect differing initial physiological states of the inner and outer cortical receptors for dopamine.

Comparison of Cotrel-Dubousset and Harrington rod instrumentations in idiopathic scoliosis.

An analysis of the efficacy of two techniques of posterior spinal instrumentation in patients with idiopathic scoliosis was performed. Thirty-two consecutive patients treated with Cotrel-Dubousset instrumentation and no external bracing were compared with 30 consecutive patients treated with Harrington rod instrumentation supplemented by Bobechko hooks, sublaminar wires, and postoperative bracing. The groups were similar in age, curve magnitude, and type. Cotrel-Dubousset instrumentation demonstrated significantly improved immediate frontal plane correction. It was also more effective in improving thoracic kyphosis, particularly in patients with preoperative hypokyphosis. Both procedures were performed with similar operative time, blood loss, and minimal complication rates.

Foot and ankle injuries in theatrical dancers.

The theatrical dancer is a unique combination of athlete and artist. The physical demands of dance class, rehearsal, and performance can lead to injury, particularly to the foot and ankle. Ankle sprains are the most common acute injury. Chronic injuries predominate and relate primarily to the repeated impact loading of the foot and ankle on the dance floor. Contributing factors include anatomic variation, improper technique, and fatigue. Early and aggressive conservative management is usually successful and surgery is rarely indicated. Orthotics play a limited but potentially useful role in treatment Following treatment, a structured rehabilitation program is fundamental to the successful return to dance.

An algorithm for arthroscopy in the over-50 age group:

We conducted a retrospective study to identify the preoperative variables that correlated with a successful outcome for knee arthroscopy in patients over the age of 50. We mailed questionnaires to 94 patients (57 responded) and reviewed their medical records and radiographs. A modified Hospital for Special Surgery knee rating system was devised. The average followup was 33 months. The percentage of those who felt they had successful results decreased with time: 82.8% felt their knees had improved immediately after postoper ative rehabilitation; this decreased to 78.1% at 6 months, 73.5% at 1 year, 65.5% at 2 years, and 50.0% at 3 years. Therefore, the subjective success rate was 67%. We performed statistical analysis of all variables to determine which had a beneficial or detrimental effect on outcome. In addition, we devised an equation to allow postoperative prediction of score. We found that age was not a factor and that radiographic findings had the greatest impact on postoperative results.

Metastatic melanoma to the spine. Demographics, risk factors, and prognosis in 114 patients.

Study Design. One-hundred-fourteen patients with metastatic melanoma of the spine were retrospectively reviewed. Objective. The goal was to define the demographics, risk factors, and prognosis for this population. Summary of Background Data. The incidence of melanoma is increasing faster than any other cancer. Therefore, orthopedic and neurologic surgeons will be increasingly confronted by patients with spinal metastases from melanoma. However, the demographics, risk factors, and prognosis remain unclear. Methods. From 7010 consecutive patients with melanoma, 114 were identified with clinically or radiographically evident spinal metastases. A comparison was made between these patients and the remainder of the population with melanoma seen at our institution using contingency table analysis with statistical significance determined by a chi-squared test. Survival data were represented by Kaplan-Meier curves, and log-rank testing was used for statistical comparisons. Results. Risk factors associated with the development of these metastases included primary lesions that were ulcerated, deeper than 0.76 mm, or of Clark level II, or located on the trunk or mucosel surfaces. The median survival time for all patients was 86 days, but this was reduced in patients with more than one metastatic site in addition to the spine. Conclusion. The prognosis for most patients with spinal metastases from melanoma is dismal. However, patients with metastatic disease limited to the spine and one other organ may survive for a relatively prolonged time and may be candidates for surgical intervention directed toward symptomatic relief.

Open fractures of the extremities. The case for open treatment.

Meticulous care of open wounds in open fractures is essential to prevent development of infection. Wounds should be treated by early excision and early delayed or secondary closure. Primary closure is not necessarily beneficial and can actually increase the risk of infection. Culture for aerobic and anerobic organisms should be obtained at initial examination, and antibiotic treatment should be started before wound excision. The experience at Duke University Medical Center, Durham, North Carolina, during the past 40 years has demonstrated that open treatment of open wounds is safe and highly successful in preventing gas gangrene and osteomyelitis.