Indirect decompression of lumbar stenosis with transpsoas interbody cages and percutaneous posterior instrumentation

BACKGROUND

The minimally invasive lateral transpsoas retroperitoneal approach to address lumbar stenosis offers advantages to traditional approaches, including sparing of the AP annulus and longitudinal ligament and less risk to the peritoneal contents and retroperitoneal vascular structures. Few studies have presented longitudinal measures of radiographic indirect decompression and relief of pain and restoration of function using the lateral approach to spine fusion.

QUESTION/PURPOSES

We determined (1) whether radiographic measures suggestive of decompression were achieved after surgery and maintained 1 year after surgery, (2) whether the intervention resulted in sustained improvements in patient-reported outcomes scores 1 year after surgery, and (3) the frequency of pseudarthrosis on CT scans at 1 year after surgery in patients with moderate or severe lumbar stenosis treated with the approach.

METHODS

Between 2008 and 2012, 158 patients were surgically treated to alleviate symptoms associated with degenerative lumbar stenosis, of whom 60 (38%) were treated with lateral lumbar interbody fusion. Of these 60 patients, 36 (60%) received CT scans preoperatively and at 1-year postoperatively and were available for radiographic analysis. Of the 60 treated patients, 16 (27%) were lost to followup before 12 months, leaving the records of 44 patients available for review of patient-reported improvements in pain and return to function. Radiographic increases in disc height, foraminal area, and canal area were measured by one observer on CT scans postoperatively and at 1 year and compared to preoperative values. Patient-reported scores, including VAS pain score and Oswestry Disability Index (ODI), were collected preoperatively and at 3 and 12 months postoperatively.

RESULTS

Increases in disc height (67%, p < 0.001), foraminal area (24%-31%, p < 0.001), and canal area (7%, p = 0.011) measured immediately postoperatively were sustained at 1-year followup. VAS pain score and ODI both improved (p < 0.001) at 3 months and were maintained at 1 year. No pseudarthroses were noted radiographically.

CONCLUSIONS

The lateral transpsoas approach to interbody fusion is capable of sustaining indirect decompression of the neural structures and resolving preoperative claudication and radiculopathy. A larger series of patients with longer followup should be studied to substantiate these early clinical results.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Effects on inadvertent endplate fracture following lateral cage placement on range of motion and indirect spine decompression in lumbar spine fusion constructs: A cadaveric study

BACKGROUND

The lateral transpsoas approach to interbody fusion is gaining popularity. Existing literature suggests that perioperative vertebra-related complications include endplate breach owing to aggressive enedplate preparation and poor bone quality. The acute effects of cage subsidence on stabilization and indirect decompression at the affected level are unknown. The purpose of this study was to compare the kinematics and radiographic metrics of indirect decompression in lumbar spines instrumented with laterally placed cages in the presence of inadvertent endplate fracture, which was determined radiographically, to specimens instrumented with lateral cages with intact endplates.

METHODS

Five levels in 5 specimens sustained endplate fracture during lateral cage implantation followed by supplementary fixation (pedicle screw/rod [PSR]: n = 1; anterolateral plate [ALP]: n = 4), as part of a larger laboratory-based study. Range of motion (ROM) in these specimens was compared with 13 instrumented specimens with intact endplates. All specimens were scanned using computed tomography (CT) in the intact, noninstrumented condition and after 2-level cage placement with internal fixation under a 400-N follower load. Changes in disc height, foraminal area, and canal area were measured and compared between specimens with intact endplates and fractured endplates.

RESULTS

Subsidence in the single PSR specimen and 4 ALP specimens was 6.5 mm and 4.3 ± 2.7 mm (range: 2.2-8.3 mm), respectively. ROM was increased in the PSR and ALP specimens with endplate fracture when compared with instrumented specimens with intact endplates. In 3 ALP specimens with endplate fracture, ROM in some motion planes increased relative to the intact, noninstrumented spine. These increases in ROM were paralleled by increase in cage translations during cyclic loading (up to 3.3 mm) and an unpredictable radiographic outcome with increases or decreases in posterior disc height, foraminal area, and canal area when compared with instrumented specimens with intact endplates.

CONCLUSIONS

Endplate fracture and cage subsidence noted radiographically intraoperatively or in the early postoperative period may be indicative of biomechanical instability at the affected level concomitant with a lack of neurologic decompression, which may require revision surgery.

Hip abductor moment arm--a mathematical analysis for proximal femoral replacement

Background

Patients undergoing proximal femoral replacement for tumor resection often have compromised hip abductor muscles resulting in a Trendelenberg limp and hip instability. Commercially available proximal femoral prostheses offer several designs with varying sites of attachment for the abductor muscles, however, no analyses of these configurations have been performed to determine which design provides the longest moment arm for the hip abductor muscles during normal function.

Methods

This study analyzed hip abductor moment arm through hip adduction and abduction with a trigonometric mathematical model to evaluate the effects of alterations in anatomy and proximal femoral prosthesis design. Prosthesis dimensions were taken from technical schematics that were obtained from the prosthesis manufacturers. Manufacturers who contributed schematics for this investigation were Stryker Orthopaedics and Biomet.

Results

Superior and lateral displacement of the greater trochanter increased the hip abductor mechanical advantage for single-leg stance and adduction and preserved moment arm in the setting of Trendelenberg gait. Hip joint medialization resulted in less variance of the abductor moment arm through coronal motion. The Stryker GMRS endoprosthesis provided the longest moment arm in single-leg stance.

Conclusions

Hip abductor moment arm varies substantially throughout the hip's range of motion in the coronal plane. Selection of a proximal femur endoprosthesis with an abductor muscle insertion that is located superiorly and laterally will optimize hip abductor moment arm in single-leg stance compared to one located inferiorly or medially.

Enhancing soft tissue ingrowth in proximal femoral arthroplasty with aortograft sleeve: a novel technique and early results

Hip abductor function is critical to joint stability after proximal femoral arthroplasty. Normal soft tissue relationships are often violated during this procedure for complete tumor resection. Abductor insufficiency leads to abnormal gait mechanics and poor function. To improve soft tissue stability about a metallic proximal femoral endoprosthesis, we devised a novel use of vascular graft material. Two patients received a proximal femoral arthroplasty using this technique. These patients were followed for an average of 26.5 months. They demonstrated mean active hip abduction of 48°, hip flexion of 90°, mean Musculoskeletal Tumor Society score of 24 (80%), and Toronto Extremity Salvage Score of 80. We believe that this technique may be useful in achieving soft tissue stability about a metal endoprosthesis and may facilitate better function in patients undergoing this surgery.

What is the emotional acceptance after limb salvage with an expandable prosthesis?

BACKGROUND

Limb preservation surgery for extremity sarcomas offers the promise of improved function and cosmesis over amputation. Application of limb salvage surgery for pediatric patients with expandable metallic endoprostheses is gaining acceptance. The few studies reporting these devices have focused on functional outcomes; one has addressed quality of life.

QUESTIONS/PURPOSES

We asked the following questions: (1) how happy are these patients; (2) how do these patients perceive their bodies; (3) do these children have difficulty with social interactions; and (4) how satisfied are patients and their parents with their outcomes?

METHODS

We retrospectively identified and contacted 26 living patients who underwent limb salvage with an expandable device. The Pediatric Outcomes Data Collection Instrument was administered to 15 of the 26 families. Attention was paid to the happiness domain of the Pediatric Outcomes Data Collection Instrument and specific answers within this domain were reported.

RESULTS

Children who received limb salvage with an expandable endoprosthesis showed high emotional satisfaction with their outcome. Overall patients reported excellent perceptions of body image and physical attractiveness. Most patients reported frequent social interactions with their peers and no difficulty with making new friends.

CONCLUSIONS

Although this study has a limited number of subjects and no control group, the data correlate with previously scores and indicate a high degree of emotional acceptance after limb salvage with an expandable endoprosthesis in a pediatric population.

Purse-string capsule repair to reduce proximal femoral arthroplasty dislocation for tumor--a novel technique with results

Hip joint dislocation is the most common complication after proximal femoral arthroplasty with a large endoprosthesis. Average dislocation rates are around 15%. In an attempt to decrease dislocations after proximal femoral arthroplasty for tumor resections, we devised a novel closure of the hip capsule. This technique uses a 3-mm cottony Dacron suture placed about the hip capsule in a circumferential, purse-string manner. Thirty-nine patients received hip hemiarthroplasty with purse-string capsular closure. Seven patients were lost to follow-up, leaving 36 patients available for analysis. One patient dislocated (2.8%). We believe this technique is useful in preventing dislocation in patients undergoing proximal femoral arthroplasty for oncologic disease.

Static progressive stretch improves range of motion in arthrofibrosis following total knee arthroplasty

Arthrofibrosis is a relatively common complication after total knee arthroplasty that negatively affects function and quality of life. Static progressive stretching is a technique that has shown promising results in the treatment of contractures of the elbow, ankle, wrist and knee. This study evaluated a static progressive stretching device as a treatment method for patients who had refractory knee stiffness after total knee arthroplasty. Twenty-five patients who had knee stiffness and no improvement with conventional physical therapy modalities were treated with the device. After a median of 7 weeks (range, 3-16 weeks), the median increase in range of motion was 25 degrees (range, 8-82 degrees). The median gain in knee active flexion was 19 degrees (range, 5-80 degrees). Ninety-two percent of patients were satisfied with the results. The authors believe static progressive stretching devices may be an effective method for increasing the ranges of motion and satisfaction levels of patients who develop arthrofibrosis after total knee arthroplasty.

Percutaneous drilling for the treatment of atraumatic osteonecrosis of the ankle

Atraumatic osteonecrosis of the ankle can be severely debilitating and can lead to joint collapse. A relatively new technique of percutaneous drilling has previously been used to relieve the symptoms of osteonecrotic hips and knees. The purpose of the present study was to examine the results of this technique when used to treat osteonecrosis of the ankle. Between September 2002 and June 2005, the senior author (M.A.M.) treated and prospectively followed 44 symptomatic osteonecrotic ankles (31 patients) using this drilling technique. The series included 23 (74.2%) women and 8 (25.8%) men with a mean age of 43 +/- 11 years. Arthrodesis had been recommended for 14 (45.2%) of these patients (20 [45.5%] ankles). At a mean follow-up duration of 45 +/- 12 months, 40 (91%) ankles had achieved a successful clinical outcome. The mean American Orthopaedic Society of Foot and Ankle Society Ankle and Hindfoot score increased from 42 +/- 5 points preoperatively to 88 +/- 10 points postoperatively, and this difference was statistically significant (P < .0001). There were no perioperative complications, although 3 ankles subsequently collapsed and required arthrodesis. The percutaneous drilling technique appears to be a useful method for the relief of symptomatic ankle osteonecrosis.

Perioperative management for orthopaedic patients with sickle cell anaemia

PURPOSE

To compare outcomes of 2 types of perioperative optimisation for patients with sickle cell anaemia (SCA) undergoing various orthopaedic surgeries.

METHODS

12 female and 11 male patients aged 13 to 40 (mean, 18) years with SCA underwent 31 separate orthopaedic procedures for osteonecrosis of the femoral head. They were referred to a haematologist for 2 types of perioperative optimisation, based on the choice of the attending paediatrician. In the aggressive management group, patients received packed red blood cells preoperatively to increase the haemoglobin level to 9 to 11 g/dl and to lower the haemoglobin S level to <30%. Fresh frozen plasma was given when their Factor VII level was <30%. In the conservative management group, patients received packed red blood cells preoperatively to increase the haemoglobin level to a minimum of 10 g/dl. Fresh frozen plasma or packed red blood cells were given intra-operatively only when excessive bleeding occurred. The length of hospital stay, the number of perioperative complications, the number of transfusions, and episodes of alloimmunisation and/or vaso-occlusive crises in the two groups were compared.

RESULTS

No patient in the aggressive management group received supplemental oxygen or had an estimated intra-operative blood loss of >400 ml. Three patients in the conservative management group received multiple intra- and post-operative transfusions and supplemental oxygen.

CONCLUSION

Both aggressive and conservative protocols may be safely used in SCA patients. The more aggressive protocol resulted in lower rates for postoperative complications, transfusions, and resorting to supplemental oxygen.

Hemostasis using a bipolar sealer in primary unilateral total knee arthroplasty

Previous studies have shown that, compared with standard electrocautery, a bipolar sealer reduces tissue damage and smoke production during surgery. We conducted a multicenter, prospective, randomized study to compare a bipolar sealer with standard electrocautery for hemostasis. Sixty-nine primary total knee arthroplasties were performed. Cohorts were evaluated for intraoperative and postoperative blood loss, blood transfusion requirements, postoperative hemoglobin and pain levels, length of hospital stay, range of motion, and Knee Society scores. Amount of blood loss and decrease in postoperative hemoglobin were significantly lower in the bipolar sealer group than in the standard electrocautery group. Need for autologous blood transfusions was decreased in the bipolar sealer group compared with the electrocautery group. There were no between-groups differences in clinical knee scores. The bipolar sealer was an effective coagulation alternative for total knee arthroplasties in reducing blood loss and transfusion requirements without affecting clinical outcome.

Small-diameter percutaneous decompression for osteonecrosis of the shoulder

Core decompression of the humeral head has previously been used as a joint-preserving procedure for treatment of symptomatic osteonecrosis of the shoulder. In this article, we describe a new decompression technique, which involves multiple small-diameter (3-mm) percutaneous perforations. In our study population (early-stage disease), shoulder arthroplasty was avoided in all 15 patients (26 shoulders) for a mean follow-up of 32 months (range, 24-41 months). Of the 26 shoulders, 25 had successful clinical and functional outcomes (University of California Los Angeles shoulder score, >24 points), and 1 showed radiographic progression of the disease but has not needed further operative treatment. We compared our decompression results with those of a nonoperative historical control group, identified through a literature search. There was a 48% (143/299) rate of progression to arthroplasty in the control group at a follow-up ranging from 2 to 4.5 years. This outpatient, percutaneous perforations technique appears to be a low-morbidity method for relieving symptoms and deferring shoulder arthroplasty in patients with symptomatic osteonecrosis of the humeral head.

Early clinical experience with the use of the Birmingham hip resurfacing system

This study reviews the early clinical experience with the Birmingham Hip resurfacing system (Smith & Nephew, Memphis, Tenn) in the United States since its approval by the FDA. A total of 230 patients were followed for a mean of 16 months (range, 6 months). There was a significant improvement in the mean preoperative Oxford hip score at the latest follow-up (44 points [range, 30-58 points] to 17 points [range, 12-28 points]). The most commonly used femoral component was 50 mm, and the mean duration of the procedures was 95 minutes (range, 65-180 min). there were 3 revisions (1.3%). Early results are favorable. As with any device, there is a continuing need for longterm monitoring and large-scale epidemiologic surveillance.

Orthopedic surgery implications of breast cancer

Breast cancer is the most common malignancy and the second leading cause of death in women. The metastatic involvement of bone denotes disease progression and decreased survival. Controversy exists regarding the exact pathophysiologic mechanism of metastasis and the different pathways that determine an osteoblastic versus osteoclastic bone compromise. Several breakthrough advances in imaging techniques aid in the detection, staging and follow-up of bone metastases. Although usually responsive to hormonal therapy and pharmacologic interventions, skeletal metastases often require some type of surgical intervention. Orthopedic surgeons should establish an active role in the multidisciplinary treatment of patients with breast cancer.

Orthopedic Surgery Options for the Treatment of Primary Osteosarcoma

Background

Osteosarcoma is the most common malignant primary neoplasm of bone. Orthopedic procedures are essential components in the multidisciplinary treatment of osteosarcoma. Limb-salvaging procedures offer adequate disease control comparable to the results obtained by amputations. This review discusses the advantages and disadvantages of the various types of amputations and the limb-salvaging techniques for the treatment of osteosarcoma.

Methods

The authors analyzed the characteristics of limb-salvaging procedures and amputations for osteosarcoma. Qualitative and quantitative studies published in the English language that are listed in the National Library of Medicine were used as the basis for this review. In addition, a review of an expandable prosthesis is included.

Results

Limb-salvaging techniques have acceptable rates of disease control. However, amputation remains a valid procedure in selected cases of osteosarcoma in most parts of the world. Orthopedic oncology surgeons have various materials, procedures, and techniques available to achieve disease control and improve function in patients with osteosarcoma.

Conclusions

The surgical management of patients with osteosarcoma is challenging. No difference in survival has been shown between amputations and adequately performed limb-salvaging procedures. Optimal tumor resection and a functional residual limb with increased patient survival are the goals of modern orthopedic oncology.

Resurfacing for Perthes disease: an alternative to standard hip arthroplasty

Metal-on-metal total hip resurfacing is an alternative to conventional total hip arthroplasty with several reports describing the benefits of this procedure in young patients. We retrospectively compared the clinical (including range-of-motion and leg length restoration) and radiographic outcome of resurfacing in young patients with Legg-Calvé-Perthes to those of patients of a similar age treated with a standard total hip arthroplasty. Eighteen patients (19 hip resurfacings) who had a mean age of 33 years (range, 18-34 years) were followed for a minimum of 26 months (mean, 51 months; range, 26-72 months). We used an anterolateral approach in four hips and a posterior approach with a trochanteric advancement in 15 hips. Eighteen of the 19 hips had Harris hip scores greater than 80 points at final followup. All patients improved range of motion while avoiding any clinically apparent impingement. Leg length was gained in 16 hips where preoperative measurements were available. The short-term results of hip resurfacing for the treatment of Perthes disease compare similarly to those found in the literature for standard total hip arthroplasty in young patients. The trochanteric advancement technique described may aid in treating the deformed femoral anatomy.

Core decompression and nonvascularized bone grafting for the treatment of early stage osteonecrosis of the femoral head

Osteonecrosis of the femoral head is a devastating disease with many patients ultimately requiring a total hip arthroplasty. When the disease is diagnosed in its early stages (before collapse of the femoral head), various procedures such as core decompression (with and without bone grafting), osteotomies, as well as nonvascularized and vascularized bone grafting can be used in an effort to preserve the joint. The efficacy of core decompression has been peer-reviewed in more than 40 studies. In general, this treatment is most successful for patients with early stage, small- and medium-sized lesions, before collapse of the femoral head. Various methods of nonvascularized bone grafting have been used. Results have varied; however, a 60% to 80% success rate has been achieved at 5- to 10-year follow-up. In the future, these procedures may be used with various other biologic adjunctive growth and differentiation factors, which may lead to higher rates of successful treatment.

New treatment approaches for osteonecrosis of the femoral head: an overview

Osteonecrosis of the femoral head is a debilitating disease that ultimately leads to hip joint destruction. Various efforts have been made in an attempt to enhance the healing of osseous defects in the femoral head before collapse occurs. Examples of noninvasive treatment modalities include pharmacologic measures, electrical stimulation, shock wave therapy, and electromagnetic field therapy. In addition, biologic alternatives will induce new bone formation. Many of these agents or techniques are still undergoing preclinical and clinical trials, and some are not approved by the Food and Drug Administration for the treatment of osteonecrosis of the femoral head. It is important to review new treatment opportunities that are currently available or on the horizon.

Systematic analysis of classification systems for osteonecrosis of the femoral head

BACKGROUND

Multiple classification systems for osteonecrosis of the hip have been developed to assist physicians in the diagnosis and treatment of this potentially debilitating disorder. The purpose of this analysis was to delineate the classification systems utilized in reports published since 1985 and, through a comparison of the most commonly used systems, to identify consistent factors that would allow for cross-publication comparisons to be made.

METHODS

We performed a PubMed search for reports of outcome studies concerning treatment methods for osteonecrosis of the hip. All studies of reported outcomes with greater than ten patients were included in the analysis. Various classification systems were tabulated to determine usage frequencies. The four most commonly used systems were then analyzed to determine common factors used for classification.

RESULTS

One hundred and fifty-seven studies were available for analysis. Sixteen major classification systems that made use of more than one radiographic factor were identified, and nine of these systems had one to five modifications reported throughout the literature. Additionally, eleven other systems made use of single factors obtained from either magnetic resonance imaging or anatomic data. The review revealed that four classification systems accounted for greater than 85.4% of the reported studies. Parameters for these four systems were stratified to allow for uniformity of patient or study evaluation.

CONCLUSIONS

This analysis of the reported classification systems for osteonecrosis of the femoral head revealed several similarities between the most commonly used systems. An analysis of patients can be made with any of the four major systems if specific data are collected according to various magnetic resonance imaging and radiographic findings. This approach will allow for easier comparison of studies across different centers.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.

Use of metal-on-metal total hip resurfacing for the treatment of osteonecrosis of the femoral head

BACKGROUND

Recently, with the advent of improved metal-on-metal prostheses, total hip resurfacing has emerged as a viable arthroplasty option. However, it remains controversial whether this procedure should be used in patients with osteonecrosis when the femoral resurfacing component is cemented onto dead bone. The purpose of this study was to analyze the clinical and radiographic outcomes of metal-on-metal total hip resurfacing arthroplasty in patients with osteonecrosis of the femoral head. In addition, this group was compared with a matched group of patients who were diagnosed as having osteoarthritis.

METHODS

Forty-two osteonecrotic hips that were treated with a metal-on-metal total hip resurfacing arthroplasty were studied. They were matched by gender, age, prosthesis, surgeon, and surgical approach to forty-two osteoarthritic hips that were treated with the same metal-on-metal prosthesis. In the osteonecrosis group, there were twenty-five men and eleven women, and in the osteoarthritis group, there were twenty-eight men and thirteen women. The mean age at the time of surgery was forty-two years. Patients were followed both clinically and radiographically for a mean of forty-one months.

RESULTS

The clinical outcomes were similar for both groups, with a good or excellent outcome in thirty-nine hips (93%) with osteonecrosis and a good or excellent outcome in forty-one hips (98%) with osteoarthritis. In each of the two groups, there were two failures that required conversion to a standard total hip arthroplasty. Survivorship curves were similar for the two patient groups.

CONCLUSIONS

The short-term results for metal-on-metal total hip resurfacing for this challenging patient population with osteonecrosis were excellent and comparable with those seen in patients with osteoarthritis. We await long-term results to see if these early results are maintained.

LEVEL OF EVIDENCE

Prognostic Level II. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.

Surgical treatment and customized rehabilitation for stiff knee arthroplasties

Treating patients who have arthrofibrotic or stiff knees after total knee arthroplasty can be difficult. Treatment with arthroscopic débridement, arthrolysis of adhesions with polyethylene spacer exchange, or complete revision arthroplasty often has led to less than optimal range of motion and functional outcomes. We used a combination of surgical arthrolysis and an intensive postoperative rehabilitation protocol, including functional bracing, to treat this condition. We then retrospectively reviewed 18 knees in 17 patients who had stiff knees after total knee arthroplasty with no other detectable clinical or radiographic abnormalities, at a mean followup of 30 months. Seventeen knees (94%) had gains in knee range of motion with a mean increased range of motion of 31 degrees. Although 16 of 17 patients had clinical improvement and were satisfied with the procedure, only (2/3) of the patients (12 of 18 patients) had excellent or good Knee Society objective scores. This combined surgical and rehabilitation method can lead to an increased range of motion. All patients improved clinically, but good functional results were less predictable. The authors think treatment of these difficult knees should be aimed at soft tissue operative releases supplemented by an intensive rehabilitation protocol.

LEVEL OF EVIDENCE

Therapeutic study, level IV (prospective study). See Guidelines for Authors for a complete description of levels of evidence.

Reductions in blood loss with use of a bipolar sealer for hemostasis in primary total knee arthroplasty

Fifty primary total knee arthroplasties were performed in a prospective, randomized study comparing the use of a bipolar sealer device versus conventional electrocautery as the method of hemostasis. Both cohorts were evaluated for intraoperative blood loss, transfusion rate, postoperative drainage, hemoglobin levels, and Knee Society scores. A significant reduction in postoperative and total blood loss was found (p = 0.05 and p = 0.02, respectively), as well as an absence of tissue charring and smoke production in the bipolar sealer group. No difference in knee scores was found between both cohorts. These results suggest that use of this bipolar sealing device is at least as effective as standard cautery devices and can reduce blood loss, tissue damage, and smoke production in total knee arthroplasties without affecting the results.