Infection After Lower-Limb Osseointegration: A Single-Center Retrospective Evaluation of Pathogens, Management, and Outcomes.

PURPOSE: Osseointegration (OI) is a novel alternative to traditional socket-suspended prostheses for lower-limb amputees, eliminating the socket-skin interface and allowing for weight bearing directly on the skeletal system. However, the stoma through which the implant attaches to the external prosthesis creates an ingress route for bacteria, and infection rates as high as 66% have been reported. The aims of this study are to classify infection management and long-term outcomes in this patient population to maximize implant salvage. METHODS: An institutional review board-approved retrospective analysis was performed on all patients who underwent lower-limb OI at our institution between 2017 and 2022. Demographic, operative, and outcome data were collected for all patients. Patients were stratified by the presence and severity of infection. Chi-square and t tests were performed on categorical and continuous data, respectively, using an alpha of 0.05. RESULTS: One hundred two patients met our study criteria; 62 had transfemoral OI and 40 had transtibial OI. Patients were followed for 23.8 months on average (range, 3.5-63.7). Osteomyelitis was more likely than soft tissue infection to be polymicrobial in nature (71% vs 23%, P < 0.05). Infections at the stoma were mostly (96%) managed with oral antibiotics alone, whereas deeper soft tissue infections also required intravenous antibiotics (75%) or operative washout (19%). Osteomyelitis was managed with intravenous antibiotics and required operative attention; 5 (71%) underwent washout and 2 (29%) underwent explantation. Both implants were replaced an average of 3.5 months after explantation. There was no correlation between history of soft tissue infection and development of osteomyelitis (P > 0.05). The overall implant salvage rate after infection was 96%. CONCLUSIONS: This study describes our institution's experience managing infection after OI and soft tissue reconstruction. Although infections do occur, they are easily treatable and rarely require operative intervention. Explantation due to infection is rare and can be followed up with reimplantation, reaffirming that OI is a safe and effective treatment modality.

Limb salvage reconstruction of the lower limb with complex ankle arthrodesis and magnetic internal lengthening nail.

PURPOSE: With advances in orthopedic implants, the use of intramedullary lengthening devices has gained increasing popularity as an alternative technique compared to lengthening with external fixators, with alleged comparable or better outcomes. The aim of this study is to report our single-center technique and outcomes of combined ankle arthrodesis and proximal tibial lengthening using external fixator with a motorized intramedullary nail, respectively. METHOD: Fourteen patients with post-traumatic advanced ankle arthritis underwent staged ankle arthrodesis with external fixator and proximal tibial lengthening using the PRECICE® ILN. Amount of shortening, length achieved, bone healing index, infection rate, ankle fusion rate, and ASAMI score were evaluated. RESULTS: The average age was 44 years old (range, 30-62). The mean follow up is 70 months (range, 43-121.4). The average amount of limb shortening for patients after ankle fusion was 36.7 mm (18-50) while lengthening was 35.9 mm (range, 18-50). Patients had the nail implanted for an average of 479 days (range, 248-730). Ankle fusions were healed in an average of 178.3 days. There were no surgical infections. All osteotomy-lengthening sites healed after an average 202 days (106-365). The mean bone healing index (BHI) was 56.0 days/cm (21.2-123.6) among the whole cohort. There were no cases of nonunion. ASAMI bone scores were excellent or good among all patients. CONCLUSION: Ankle arthrodesis with external fixation along with proximal tibial lengthening using motorized IMN yielded high rates of fusion and successful lengthening. This technique could be offered as a reasonable alternative to using external fixation for both purposes. LEVEL OF EVIDENCE: Level IV, Retrospective cohort study.

Osseointegration for Lower Limb Amputation: Understanding the Risk Factors and Time Courses of Soft Tissue Complications.

PURPOSE: Lower-limb osseointegrated prostheses are a novel alternative to traditional socket-suspended prostheses, which are often associated with poor fit, soft tissue damage, and pain. Osseointegration eliminates the socket-skin interface and allows for weight-bearing directly on the skeletal system. However, these prostheses can also be complicated by postoperative issues that can negatively impact mobility and quality of life. Little is known about the incidence of or risk factors for these complications as few centers currently perform the procedure. METHODS: A retrospective analysis was performed on all patients who underwent single-stage lower limb osseointegration at our institution between 2017 and 2021. Patient demographics, medical history, operative data, and outcomes were collected. Fisher exact test and unpaired t tests were performed to identify risk factors for each adverse outcome, and time-to-event survival curves were generated. RESULTS: Sixty patients met our study criteria: 42 males and 18 females with 35 transfemoral and 25 transtibial amputations. The cohort had an average age of 48 years (range, 25-70 years) and follow-up period of 22 months (range, 6-47 months). Indications for amputation were trauma (50), prior surgical complication (5), cancer (4), and infection (1). Postoperatively, 25 patients developed soft tissue infections, 5 developed osteomyelitis, 6 had symptomatic neuromas, and 7 required soft tissue revisions. Soft tissue infections were positively correlated with obesity and female sex. Neuroma development was associated with increased age at osseointegration. Neuromas and osteomyelitis were both associated with decreased center experience. Subgroup analysis by amputation etiology and anatomic location did not show significant differences in outcomes. Notably, hypertension (15), tobacco use (27), and prior site infection (23) did not correlate with worse outcomes. Forty-seven percent of soft tissue infections occurred in the 1 month after implantation, and 76% occurred in the first 4 months. CONCLUSIONS: These data provide preliminary insights into risk factors for postoperative complications arising from lower limb osseointegration. These factors are both modifiable (body mass index, center experience), and unmodifiable (sex, age). As this procedure continues to expand in popularity, such results are necessary to inform best practice guidelines and optimize outcomes. Further prospective studies are needed to confirm the above trends.

Ankle Distraction Arthroplasty: A Survivorship Review and Meta-Analysis.

Multiple treatments exist for ankle osteoarthritis. Ankle arthrodesis is the gold standard in late-stage osteoarthritis, but sacrifices range of motion and risks nonunion. Total ankle arthroplasty is typically reserved for low-demand patients as the long-term outcomes are poor. Ankle distraction arthroplasty is a joint sparing procedure which utilizes external fixator frame to unload the joint. This promotes chondral repair and improves function. This study aimed to organize clinical data and survivorship in published papers and direct further research efforts. Thirty-one publications were evaluated and 16 were included in the meta-analysis. The Modified Coleman Methodology Score was used to assess quality of the individual publications. Random effects models were used to estimate the failure risk after ankle distraction arthroplasty. Ankle Osteoarthritis Score (AOS), American Orthopedic Foot and Ankle Score (AOFAS), Van Valburg, and Visual Analog Scores (VAS) all improved postoperatively. Random effects model analysis revealed an overall failure ratio of 11% (95% CI: 7%-15%; p value ≤ .001; I2 = 87.01%) after 46.68 ± 7.17 months follow up, 9% (95% CI: 5%-12%; p value≤0.001 I2=81.59%) with less than 5 years follow-up and 28% (95% CI: 16%-41%; p value≤0.001 I2=69.03%) for patients with more than 5 years follow-up. Ankle Distraction Arthroplasty has promising short to intermediate term outcomes which makes this a reasonable treatment option to delay joint sacrificing surgery. The selection of the optimal candidates and consistent technique would improve research and subsequently outcomes. Based on our meta-analysis, negative prognostic factors include female sex, obesity, ROM < 20°, leg muscle weakness, high activity level, low preoperative pain levels, higher preoperative clinical scores, inflammatory arthritis, septic arthritis, and deformity.

A Cost-Benefit Analysis of Osseointegrated Prostheses for Lower Limb Amputees in the US Health Care System.

BACKGROUND: Patients with transfemoral and transtibial amputations generally rely on socket-suspended (SS) prostheses for ambulation. The use of these aids can be complicated by poor fit, leading to tissue damage, pain at the socket-limb interface, and inability to ambulate. Osseointegrated implants (OIs) directly anchor a prosthesis to the patient's residual limb, eliminating these issues. However, they require customized components and additional surgeries. The purpose of this study was to conduct the first cost-benefit analysis of OI prostheses compared to SS prostheses for lower limb amputees in the United States. METHODS: A retrospective chart review was performed on all patients who received unilateral lower limb OI prostheses at our institution. Costs were calculated in a bottom-up approach using Current Procedural Terminology codes. Utilities and SS prosthesis costs were derived from previous studies. A Monte Carlo model was used to project costs and lifetime quality-adjusted life years for OI and SS prostheses, and the incremental cost-effectiveness ratio (ICER) of OI compared SS prostheses was determined. RESULTS: Twenty-five patients (12 female) were included in the study. The mean follow-up was 17 months postimplantation. The average cost of OI surgery was $54,463. Twenty percent of patients required preimplantation soft tissue revision surgery ($49,191). Complication rates per year and average costs were as follows: soft tissue infection (29%, $435), bone/implant infection (11%, $11,721), neuroma development (14%, $14,659), and mechanical failure (17%, $46,513). The ICER was $44,660. A cost-effectiveness acceptability curve demonstrated that OI was favored over SS in 78% of cases at a willingness-to-pay of $100,000 per quality-adjusted life year. In a 1-way sensitivity analysis, the ICER was most sensitive to the mechanical failure rate, mechanical failure cost, and prior SS prosthesis costs. CONCLUSIONS: The model shows that OI prostheses provide a higher quality of life at affordable costs when compared to poorly tolerated SS prostheses in patients with lower limb amputations in the United States. The cost-effectiveness is largely determined by the patient's previous SS prosthesis costs and is limited by the frequency and costs of OI mechanical failure. More research must be done to understand the long-term benefits and risks of OI prostheses.

STRYDE versus PRECICE magnetic internal lengthening nail for femur lengthening.

INTRODUCTION: Magnetic internal lengthening nails (MILNs) have been used for femoral lengthening to avoid complications associated with external fixation. The titanium version of the MILN (PRECICE®) has been in use since 2011 but had limitations (50-75 lb) in post-operative weight bearing. A new stainless-steel version of the MILN (STRYDE®) allows 150-250 lb of post-operative weight bearing. The aim is to compare the outcomes of using these two different MILNs for both unilateral and bilateral femoral lengthening. METHODS: A single-center, retrospective cohort study was conducted in which patients' records were reviewed from the period from January 2017 to March 2020. A total of 66 femoral lengthening procedures were included in the study and were divided into two groups: STRYDE® group (30 femora) and PRECICE® group (36 femora). Outcomes assessed were the 6-months post-operative Limb Deformity-Scoliosis Research Society (LD-SRS) Score, adjacent joint range of motion (ROM), average distraction rate, bone healing index (BHI), and complications. RESULTS: No statistically significant difference was found between the two groups in regard to the (LD-SRS) score, hip ROM, or knee ROM. Statistically significant differences were found between the two groups in regard to BHI (average of 0.84 months/cm and 0.67 months/cm for STRYDE® and PRECICE®, respectively) and distraction rate (average of 0.6 mm/day and 0.9 mm/day for STRYDE® and PRECICE®, respectively). No mechanical nail complications were reported in the STRYDE® group compared to three events of nail failure in the PRECICE® group. One femur in the PRECICE® group needed BMAC injection for delayed healing compared to four femurs in the STRYDE® group. CONCLUSION: The STRYDE® MILN yields comparable functional results to those of PRECICE® MILN and shows fewer mechanical nail complications. However, STRYDE® MILN requires a slower distraction rate and yields slower healing (larger BHI). LEVEL OF EVIDENCE: Level III, Therapeutic study.

Limb Lengthening in Russell-Silver Syndrome: An Update Confirming Safe and Speedy Healing.

INTRODUCTION: Russell-Silver syndrome (RSS) is a unique cause of syndromic, and often severe, limb length discrepancy (LLD). RSS causes growth retardation both in utero and postnatally, with asymmetry in limb length more noticeable as growth progresses throughout childhood and adolescent. We aim to present the largest cohort in the literature on limb lengthening in patients with RSS and to validate previous literature supporting faster bony consolidation in these patients with more robust data. We further aim to establish differences in healing within this cohort based on age, sex, segment lengthened, or type of lengthening procedure performed, to help refine patient expectations and guide practitioners in treating this population. METHODS: This was a retrospective study of patients with a diagnosis of RSS who underwent a limb lengthening procedure for the purpose of limb equalization. They were compared with a historic control group of patients who underwent limb lengthening for LLD of a non-RSS etiology. The primary outcome measure was bone healing index (BHI). RESULTS: The RSS group consisted of 24 patients with 29 segments lengthened, and was compared with a historic control group consisting of 20 patients with 22 segments lengthened (Goldman). Patients with RSS had a significantly lower BHI, and therefore faster healing of their lengthening site, than their non-RSS peers (P=0.02). Within the RSS cohort, we did not detect a difference in BHI based on intervention type or sex, but we did find a trend toward faster healing in femurs over tibiae (P=0.08), and established that younger patients tended toward lower BHIs (P<0.01). CONCLUSIONS: Our results confirmed with more robust data the prior finding that patients with RSS may undergo limb lengthening procedures at least as safely as their non-RSS counterparts, and with even faster bony consolidation, especially in younger patients. We hypothesize that concurrent treatment with growth hormone supplementation may contribute to this finding, although further study is necessary. This is the largest cohort of RSS patients treated with limb lengthening for LLD reported in the literature, and these findings will help to guide surgeon decision-making when treating this unique population. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

Knee Joint Bone Defects: Reconstruction With Bone Transport and Arthrodesis.

BACKGROUND: The increasing in primary total knee arthroplasty has led to an increase in infectious complications, revision surgery, and bone loss. Knee joint bone defects (KJBD) may be managed using bone transport and arthrodesis with Ilizarov or bone transport over nail (BTON) techniques. The aim of this study is to compare both techniques in the reconstruction of KJBDs. METHODS: This was a retrospective cohort study of 29 patients with extensive KJBD. All patients underwent reconstruction of the KJBD using bone transport (either Ilizarov or BTON techniques). The primary outcome variables for comparison between the two groups included time in frame (days), external fixation index (EFI, days/cm), residual limb length discrepancy (cm), and complications (Caton classification). RESULTS: Gender and age profiles were comparable. Mean time spent in frame for bone transport was 566 days (σ = 236, 95% CI 429-702) for the Ilizarov cohort and 191 days (σ = 162, 95% CI 101-280) for BTON (P < .0001). EFI for the period of bone transport was 75.1 d/cm (σ = 41.5, 95% CI 51.1- 99.1) for the Ilizarov cohort and 24.7 d/cm (σ = 24.0, 95% CI 11.4-38) for BTON (P = .0004). Union, limb length discrepancy and complication rates were comparable between both groups. CONCLUSION: For the management of KJBD after failed total knee arthroplasty, BTON is preferred due to significantly less time spent in frame, lower EFI, and higher rates of normal mechanical alignment. The Ilizarov method may be useful when there is a contraindication to BTON.

Subtalar distraction arthroplasty with bone marrow aspirate concentrate (BMAC), preliminary results of a new joint preservation technique.

INTRODUCTION: Isolated subtalar osteoarthritis (OA) is a debilitating condition usually occurring after trauma and particularly in the setting of an intraarticular calcaneal fracture. Currently, subtalar (talo-calcaneal joint) fusion surgery is the treatment of choice in managing subtalar OA after failure of conservative treatment. Unfortunately, subtalar fusion eliminates joint motion and increases the load over the adjacent midfoot and ankle joints, which affects the outcome of the surgery over time. Popular in the ankle, distraction arthroplasty offers another joint-preserving option, particularly important for active patients. In contrast to fusion as a salvage procedure, subtalar distraction arthroplasty allows the possibility of maintaining the function of the arthritic subtalar joint while reducing pain and improving the overall function of the foot and ankle. METHODS: We performed subtalar distraction arthroplasty using a circular external fixator combined with BMAC on seven patients with symptomatic and refractory subtalar OA. All these patients were interested in an alternative to fusion. We obtained clinical and radiographic data before and after surgery. Ankle Osteoarthritis Score (AOS) and the Marijnissen Distraction Clinical Score (MDCS) were obtained before surgery, after one year, and at latest follow-up. RESULTS: The average age was 56 years (range 45-69). The mean duration of post-operative follow-up was 35.4 months (range 15.2-53.5). The inversion of the ankle joint changed from 16.9° (10°-25°) pre-operatively to 14.3° (10°-20°) post-operatively (P = 0.28), and the eversion from 5.6° (0°-10°) to 10.0° (0°-20°) (P = 0.17). We found an increase in subtalar joint space from 1.4 mm (0-3) to 2.6 mm (2-4) before and after surgery (P = 0.01), respectively. Finally, Pixel Density Ratio (PDR) increased from 0.87 (0.66-1.30) to 1.01 (0.89-1.18) (P = 0.19). Compared to pre-operative conditions, we observed a decrease in subchondral sclerosis on X-ray in all cases post-operatively. The AOS score for ankle pain improved from 58.8 (47-74) to 15.1 (0-31) (p < 0.01). The AOS score for ankle disability improved from 68.2 (57-81) to 16.1 (0-43.5) (p < 0.001). We found improvement in the MDCS over time for all measured parameters. The clinical condition improved from 1.4 (0-2) to 0.8 (0-2) after one year and to 0.3 (0-2) at the latest follow-up (p < 0.001). Mobility was measured as ROM in the treated ankle relative to each patient's contralateral ankle. This increased from 35% (0-100) to 66% (15-120) to 76% (15-100) (p = 0.059). Function improved from 2.3 (0-3) to 1.3 (0-3) to 0.6 (0-3) (p < 0.001). Pain decreased from 7.4 (2-10) to 4.4 (2-8) to 2.1 (0-7) (p < 0.01). Complications include one patient with sensory neuralgia. CONCLUSIONS: Preliminarily, results of subtalar distraction arthroplasty as a new joint preservation technique are encouraging. Our research suggests the possibility of subtalar distraction arthroplasty as an effective treatment for symptomatic subtalar OA. Furthermore, this new operation does not eliminate the possibility of a future surgery like fusion. Subtalar distraction arthroplasty can be helpful in the management of subtalar OA in active patients who desire preservation of foot and ankle motion.

Soft Tissue Contouring at the Time of Osseointegrated Implant Reconstruction for Lower Extremity Amputation.

INTRODUCTION: Patients with lower extremity amputations using a classic socket prosthesis face many challenges related to the socket-limb interface. The adaptation of osseointegration has allowed for the attachment of a prosthesis directly to bone, eliminating this interface and providing mechanical benefits. Contrary to the socket prosthesis, the osseointegrated prosthesis requires reducing and minimizing the soft tissue envelope. Studies have shown that patients who have undergone placement of these implants have high rates of reoperation for soft tissue redundancy. The purpose of our study was to evaluate complication rates and need for revisional surgery using our technique of soft tissue closure around the prosthesis at the time of implant placement. METHODS: An institutional review board-approved, retrospective chart review was performed on all patients who underwent implantation of an osseointegrated prosthesis for lower extremity amputation with concomitant plastic surgery closure at our institution during a 2-year period from June 2017 to June 2019. Patient demographics, health status descriptors, operative data, length of admission, and rates of postoperative complications were gathered from the electronic medical record and coded into a HIPAA-compliant database. Specific outcomes tracked included minor and major infection, osteomyelitis, implant failure, hematoma, seroma, delayed wound healing, and rates of reoperation and readmission. RESULTS: There were a total of 14 patients who underwent osseointegrated implant placement with concomitant plastic surgical coverage of the prosthesis during the study period. The average patient age was 50 years (range, 26-70 years), and average body mass index was 32.2 kg/m (range, 19.7-44.8 kg/m). Average follow-up time was 28 weeks (range, 10-73 weeks). There were 2 cases of local infection resolved with a course of oral antibiotics. There were no instances of infection requiring procedural intervention or hospital admission, nor any cases of osteomyelitis. Two patients required outpatient surgery for exchange of implant abutment, one required revision of a prosthesis for hardware loosening, and one required targeted muscle reinnervation of a sciatic nerve neuroma. There were no patients who required revisional surgery for soft tissue redundancy and no cases of delayed wound healing. CONCLUSIONS: Adequate planning of incisions and soft tissue contouring is important in the care of osseointegrated patients. Plastic surgery involvement can decrease soft tissue complications and lead to improved patient outcomes.

The PRECICE magnetic IM compression nail for long bone nonunions: a preliminary report.

INTRODUCTION: The magnetic intramedullary (IM) compression nail is capable of providing sustained compression for the treatment of nonunions of long bones. This ability was previously only possible with the use of external fixation. We asked the following questions: How effective is the IM compression nail at achieving union? How do we know when adequate compression has been attained? Which types of nonunions are good candidates for this treatment? MATERIALS AND METHODS: Fourteen patients with nonunions of the tibia (5) or femur (9) were treated with the PRECICE IM compression nail. The average age was 49 years number of previous surgeries was 1.9, 7 were atrophic and 7 normotrophic, 3 were metaphyseal and 11 diaphyseal. All PRECICE IM nails were pre-distracted prior to implantation. Compression was applied post-operatively until the locking bolts were seen on X-ray to be bending or the nail was no longer shortening despite applying the external magnet. RESULTS: Union was achieved in 13/14 cases. The time to union was 24.5 weeks (range 11-60). The two proximal tibia metaphyseal nonunions, both deformed into varus (4°) and flexion (10°) after compression was applied with one failing to unite. The distal tibia metaphyseal and diaphyseal nonunions did not deform upon compression. Three patients had positive cultures and were treated with IV antibiotics for 6 weeks followed by 3 months of oral suppression without subsequent infection. No mechanical nail failures were seen. CONCLUSIONS: The IM compression nail was successful at applying compression, preventing deformity, and obtaining union in all diaphyseal and in distal tibia metaphyseal nonunions. Signs of active compression are bending of the locking bolts and failure of the nail to shorten. Proximal tibia metaphyseal nonunion may not be suited for this treatment.

Predicting the Feasibility of Correcting Mechanical Axis in Large Varus Deformities With Unicompartmental Knee Arthroplasty.

BACKGROUND: Due to disappointing historical outcomes of unicompartmental knee arthroplasty (UKA), Kozinn and Scott proposed strict selection criteria, including preoperative varus alignment of ≤15°, to improve the outcomes of UKA. No studies to date, however, have assessed the feasibility of correcting large preoperative varus deformities with UKA surgery. The study goals were therefore to (1) assess to what extent patients with large varus deformities could be corrected and (2) determine radiographic parameters to predict sufficient correction. METHODS: In 200 consecutive robotic-arm assisted medial UKA patients with large preoperative varus deformities (≥7°), the mechanical axis angle (MAA) and joint line convergence angle (JLCA) were measured on hip-knee-ankle radiographs. It was assessed what number of patients were corrected to optimal (≤4°) and acceptable (5°-7°) alignment, and whether the feasibility of this correction could be predicted using an estimated MAA (eMAA, preoperative MAA-JLCA) using regression analyses. RESULTS: Mean preoperative MAA was 10° of varus (range, 7°-18°), JLCA was 5° (1°-12°), postoperative MAA was 4° of varus (-3° to 8°), and correction was 6° (1°-14°). Postoperative optimal alignment was achieved in 62% and acceptable alignment in 36%. The eMAA was a significant predictor for optimal postoperative alignment, when corrected for age and gender (P < .001). CONCLUSION: Patients with large preoperative varus deformities (7°-18°) could be considered candidates for medial UKA, as 98% was corrected to optimal or acceptable alignment, although cautious approach is needed in deformities >15°. Furthermore, it was noted that the feasibility of achieving optimal alignment could be predicted using the preoperative MAA, JLCA, and age.

Humerus Lengthening With the PRECICE Internal Lengthening Nail.

BACKGROUND: Deformity and growth arrest of the humerus in children may result as sequelae of proximal humerus fractures and unicameral bone cysts, or as complications of their treatment. As approximately 80% of the growth of the humerus arises from the proximal physis, the resultant upper limb-length discrepancy can be substantial. Benefits to lengthening the shortened arm have been previously demonstrated with the use of external fixation devices. To our knowledge, no reports have been published on the use of intramedullary implants for this purpose. METHODS: A 15-year-old girl with humeral shortening secondary to proximal humeral growth disturbance following treatment for a unicameral bone cyst was treated with humeral osteoplasty and gradual lengthening with an off-label use of a fully implantable motorized intramedullary lengthening nail. A varus proximal humeral deformity and lateral starting point allowed for avoidance of the rotator cuff insertion. RESULTS: Humeral lengthening (5 cm) was achieved at 9 weeks, with bony union at 7 months, and hardware removal at 9½ months. Shoulder and elbow motion was maintained during and after treatment. CONCLUSIONS: This is the first case report of humeral lengthening using a fully implantable motorized intramedullary lengthening nail. Although some technical limitations remain when compared with other methods, the procedure was well tolerated throughout the course of treatment. LEVEL OF EVIDENCE: Level IV-case report.

Total Hip Arthroplasty in Patients With Multifactorial Perceived Limb Length Discrepancy.

BACKGROUND: Patients with advanced hip arthritis can present with multifactorial limb length discrepancies (LLDs) owing to bony shortening from growth arrest, proximal hip migration, soft-tissue contractures, and pelvic obliquity. The patient perceives an LLD that is a combination of true LLD and apparent LLD. METHODS: We retrospectively reviewed 7 cases with multifactorial mean perceived LLD of 7.7 cm (range, 3.6-11 cm) that underwent primary total hip arthroplasty and auxiliary soft-tissue procedures. Perceived LLD, true LLD, and apparent LLD were defined and were compared before and after surgery in this cohort of patients with a mean follow-up of 57.4 months. RESULTS: The mean perceived LLD at final follow-up was 1.0 ± 0.9 cm compared with that of 7.7 ± 2.6 cm preoperatively (P < .05). Postoperative true LLD was 0.7 ± 0.8 cm compared with that of 3.2 ± 0.8 cm preoperatively (P < .05). At final follow-up, all 7 patients were ambulating without any assistive devices and were satisfied with their surgical outcome. CONCLUSION: With careful preoperative clinical and radiographic assessments as well as planning for multifactorial perceived LLD, this can be adequately corrected with primary total hip arthroplasty and auxiliary soft-tissue procedures resulting in good radiologic and functional outcomes.

Does Integrated Fixation Provide Benefit in the Reconstruction of Posttraumatic Tibial Bone Defects?

BACKGROUND: Limb salvage in the presence of posttraumatic tibial bone loss can be accomplished using the traditional Ilizarov method of distraction osteogenesis with circular external fixation. Internal fixation placed at the beginning of the consolidation phase, so-called integrated fixation, may allow for earlier removal of the external fixator but introduces concerns about cross-contamination from the additional open procedure and maintenance of bone regenerate stability. QUESTIONS/PURPOSES: Among patients deemed eligible for integrated fixation, we sought to determine: (1) Does integrated fixation decrease the time in the external fixator? (2) Is there a difference in the rate of complications between the two groups? (3) Are there differences in functional and radiographic results between integrated fixation and the traditional Ilizarov approach of external fixation alone? METHODS: Between January 2006 and December 2012, we treated 58 patients (58 tibiae) with posttraumatic tibial bone loss using the Ilizarov method. Of those, 30 patients (52%) were treated with the "classic technique" (external fixator alone) and 28 (48%) were treated with the "integrated technique" (a combination of an external fixator and plating or insertion of an intramedullary nail). During that period, the general indications for use of the integrated technique were closed physes, no active infection, and a healed soft tissue envelope located at the intended internal fixation site; the remainder of the patients were treated with the classic technique. Followup on 30 (100%) and 28 (100%) patients in the classic and integrated techniques, respectively, was achieved at a minimum of 1 year (mean, 3 years; range, 1-8 years). Adverse events were reported as problems, obstacles, and complications according to the publication by Paley. Problems and obstacles are managed by nonoperative and operative means, respectively; in addition, they resolve completely with treatment. Complications, according to the Paley classification, result in permanent sequelae. Functional and radiographic results were reported using the Association for the Study and Application of Methods of Ilizarov scoring system. RESULTS: Overall, there was a mean of four (range, 2-5) surgical procedures to complete the tibial reconstruction with a similar incidence of unplanned surgical procedures (obstacles) between the two groups (p = 0.87). Patients treated with integrated fixation spent less time in the external fixator, 7 months (range, 5-20 months) versus 11 months (range, 1-15 months; p < 0.001). There were seven problems, 15 obstacles, and zero complications in the classic group. Ten problems, 15 obstacles, and one complication occurred in the integrated fixation group. There was no difference in the severity (p = 0.87) or number (p = 0.40) of complications between both groups. Good to excellent Association for the Study and Application of Methods of Ilizarov function and bone scores were obtained in 100% and 98% of patients, respectively. CONCLUSIONS: The integrated fixation method allows for a more efficient limb salvage surgical reconstruction in patients carefully selected for that approach, whereas the frequency of adverse events and ability to restore limb lengths was not different between the groups with the numbers available. Careful placement of external fixation pins is critical to decrease cross-contamination with planned internal fixation constructs. In this study of posttraumatic tibial bone defect reconstruction, good/excellent results were found in all patients after a mean of four surgical procedures; however, a larger multicenter prospective study would allow for more robust and generalizable conclusions. LEVEL OF EVIDENCE: Level III, therapeutic study.

What is the Utility Of a Limb Lengthening and Reconstruction Service in an Academic Department of Orthopaedic Surgery?

BACKGROUND: Limb lengthening and reconstruction surgery is a relatively new subspecialty of orthopaedic surgery in the United States. Despite increased awareness and practice of the specialty, it is rarely vested as a separate clinical service in an academic department of orthopaedic surgery. We have had experience growing such a dedicated service within an academic department of orthopaedic surgery over the past 9 years. QUESTIONS/PURPOSES: We explored (1) the use of a limb deformity service (LDS) in an academic department of orthopaedic surgery by examining data on referral patterns, our clinical volume, and academic productivity; and (2) the surgical breadth of cases comprising the patients of the LDS in an academic department of orthopaedic surgery by examining data on caseload by anatomic sites, category, and surgical techniques/tools. METHODS: We (SRR, ATF, EWB) retrospectively examined data on numbers of surgical cases and outpatient visits from the limb lengthening and complex reconstruction service at the Hospital for Special Surgery from 2005 to 2013 to evaluate growth. We studied 672 consecutive surgical cases performed by our service for a sample period of 1 year, assessing referral patterns within and outside our medical center, anatomic region, surgical category, and surgical technique/tool. Academic productivity was measured by review of our service's publications. RESULTS: During the time period studied (2005-2013), outpatient and surgical volume significantly increased by 120% (1530 to 3372) and 105% (346 to 708), respectively, on our LDS. Surgical volume growth was similar to the overall growth of the department of orthopaedic surgery. Referrals were primarily from orthopaedic surgeons (56%) and self/Internet research (25%). Physician referrals were predominantly from our own medical center (83%). Referrals from within our institution came from a variety of clinical services. Forty-nine peer-reviewed articles and 23 book chapters were published by staff members of our service. Anatomic surgical sites, surgical categories, and technique/tools used on our LDS were diverse, yet procedures were specialized to the discipline of limb deformity. CONCLUSIONS: There is a substantial role for an LDS within an academic department of orthopaedic surgery. With establishment of a dedicated service comes focus and resources that establish an environment for growth in volume, intramural and extramural referral, and purposeful research and education. The majority of referrals were from orthopaedic surgeons from our own medical center, suggesting needfulness. The LDS provides patients access to specialized surgery. The number of intramural referrals suggests that the specialty service helps retain patients within our academic orthopaedic department. Future research will try to determine if such a dedicated service leads to improved outcomes, efficiency, and value. LEVEL OF EVIDENCE: Level IV, retrospective study.

Motorized intramedullary nail for management of limb-length discrepancy and deformity.

Distraction osteogenesis has been used for more than 50 years to address limb-length discrepancy and deformity. Intramedullary fixation has been used in conjunction with external fixation to decrease the time in the external fixator and prevent deformity and refracture. A new generation of motorized intramedullary nails is now available to treat limb-length discrepancy and deformity. These nails provide bone fragment stabilization and lengthening with reliable remote-controlled mechanisms, obviating the need for external fixation. Motorized intramedullary nails allow accurate, well-controlled distraction, and early clinical results have been positive.

Precision of the PRECICE internal bone lengthening nail.

BACKGROUND: Previous designs of internal bone lengthening devices have been fraught with imprecise distraction, resulting in nerve injuries, joint contractures, nonunions, and other complications. Recently, a magnet-operated PRECICE nail (Ellipse Technologies, Inc, Irvine, CA, USA) was approved by the FDA; however, its clinical efficacy is unknown. QUESTIONS/PURPOSES: We evaluated this nail in terms of (1) accuracy and precision of distraction, (2) effects on bone alignment, (3) effects on adjacent-joint ROM, and (4) frequency of implant-related and non-implant-related complications. METHODS: We reviewed medical and radiographic records of 24 patients who underwent femoral and/or tibial lengthening procedures using the PRECICE nail from August 2012 to July 2013 for conditions of varied etiology, the most common being congenital limb length discrepancy, posttraumatic growth arrest, and fracture malunion. This group represented 29% of patients (24 of 82) who underwent a limb lengthening procedure for a similar diagnosis during the review period. At each postoperative visit, the accuracy and precision of distraction, bone alignment, joint ROM, and any complications were recorded by the senior surgeon (SRR). Accuracy reflected how close the measured lengthening was to the prescribed distraction at each postoperative visit, while precision reflected how close the repeated measurements were to each other over the course of total lengthening period. No patients were lost to followup. Minimum followup from surgery was 3 weeks (mean, 14 weeks; range, 3-29 weeks). RESULTS: Mean total lengthening was 35 mm (range, 14-65 mm), with an accuracy of 96% and precision of 86%. All patients achieved target lengthening with minimal unintentional effects on bone alignment. The knee and ankle ROM were minimally affected. Of the complications requiring return to the operating room for an additional surgical procedure, there was one (4%) implant failure caused by a nonfunctional distraction mechanism and six (24%) non-implant-related complications, including premature consolidation in one patient (4%), delayed bone healing in two (8%), delayed equinus contracture in two (8%), and toe clawing in one (4%). CONCLUSIONS: We conclude that this internal lengthening nail is a valid option to achieve accurate and precise limb lengthening to treat a variety of conditions with limb shortening or length discrepancy. Randomized, larger-sample, long-term studies are required to further confirm clinical efficacy of these devices, monitor for any late failures and complications, and compare with other internal lengthening devices with different mechanisms of operation. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

What risk factors predict usage of gastrocsoleus recession during tibial lengthening?

BACKGROUND: Tibial lengthening is frequently associated with gastrocsoleus contracture and some patients are treated surgically. However, the risk factors associated with gastrocsoleus contracture severe enough to warrant surgery during tibial lengthening and the consistency with which gastrocsoleus recession (GSR) results in a plantigrade foot in this setting have not been well defined. QUESTIONS/PURPOSES: We compared patients treated with or without GSR during tibial lengthening with respect to (1) clinical risk factors triggering GSR use, (2) ROM gains and patient-reported outcomes, and (3) complications after GSR. METHODS: Between 2002 and 2011, 95 patients underwent tibial lengthenings excluding those associated with bone loss; 82 (83%) were available for a minimum followup of 1 year. According to our clinical algorithm, we performed GSR when patients had equinus contractures of greater than 10° while lengthening or greater than 0° before or after lengthening. Forty-one patients underwent GSR and 41 did not. Univariate analysis was performed to assess independent associations between surgical characteristics and likelihood of undergoing GSR. A multivariate regression model and receiver operating characteristic curves were generated to adjust for confounders and to establish risk factors and any threshold for undergoing GSR. Chart review determined ROM, patient-reported outcomes, and complications. RESULTS: Amount and percentage of lengthening, age, and etiology were risk factors for GSR. Patients with lengthening of greater than 42 mm (odds ratio [OR]: 4.13; 95% CI: 1.82, 9.40; p = 0.001), lengthening of greater than 13% of lengthening (OR: 3.88; 95% CI: 1.66, 9.11; p = 0.001), and congenital etiology (OR: 1.90; 95% CI: 0.86, 4.15; p = 0.109) were more likely to undergo GSR. Adjusting for all other variables, increased amount lengthened (adjusted OR: 1.05; 95% CI: 1.02, 1.07; p < 0.001) and age (adjusted OR: 1.02; 95% CI: 0.99, 1.05; p = 0.131) were associated with undergoing GSR. Patients gained 24° of ankle dorsiflexion after GSR. Self-reported functional outcomes were similar between patients with or without GSR. Complications included stretch injury to the posterior tibial nerve leading to temporary and partial loss of plantar sensation in two patients. CONCLUSIONS: Dorsiflexion was maintained and/or restored similarly among patients with or without GSR when treated under our algorithm. Functional compromise was not seen after GSR. Identification of patients at risk will help surgeons indicate patients for surgery. Acute dorsiflexion should be avoided to minimize risk of injury to the posterior tibial nerve. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Recombinant human BMP-2 increases the incidence and rate of healing in complex ankle arthrodesis.

BACKGROUND: Although its FDA-approved applications are limited, the pro-osteogenic benefits of recombinant human BMP-2 (rhBMP-2) administration have been shown in off-label surgical applications. However, the effects of rhBMP-2 on ankle fusions are insufficiently addressed in the literature, which fails to include a case-control study of adequate sample size to evaluate the efficacy of rhBMP-2 treatment. QUESTIONS/PURPOSES: In this study we asked whether rhBMP-2 treatment (1) would increase the rate of successful ankle fusion in complex patients (patients with comorbidities associated with poor surgical healing) compared with a control group of patients undergoing ankle fusion who did not receive rhBMP-2; (2) would reduce total time wearing a frame when compared with the control group; (3) would result in a difference in the percentage of bone bridging between the group treated with rhBMP-2 and the control group, as determined by CT scans 3 months after surgery; and (4) would encounter an equal rate of complications different from untreated patients. METHODS: A retrospective chart study was performed on 82 patients who, because of a host of comorbidities associated with poor healing, required a complex ankle arthrodesis with the Ilizarov technique. The first 40 patients did not receive rhBMP-2, whereas the subsequent 42 patients received intraoperative rhBMP-2. Time wearing the frame was determined by chart review; decision to remove the frame was made by the surgeon based on quantitative bone bridging measured using a CT scan taken 3 months after fusion. RESULTS: Patients treated with rhBMP-2 were more likely to obtain fusion after the initial surgery (93% versus 53%, p < 0.001; OR, 11.76; 95% CI, 3.12-44.41), spent less total time wearing the frame (124 versus 161 days, p < 0.01), and showed more bone bridging on CT scans (48% versus 32%, p < 0.05). All patients with greater than 30% bone bridging observed on CT scans 3 months postoperatively achieved successful union without further intervention. CONCLUSIONS: Our findings suggest that rhBMP-2 is a beneficial adjunct for selected groups of patients undergoing complex ankle arthrodesis. CT is a promising modality in the assessment of bone healing in ankle fusion. A proper randomized controlled trial remains necessary to fully describe the efficacy of rhBMP-2 in accelerating bone healing.