The Influence of Tibial Positioning on the Diagnostic Accuracy of Combined Posterior Cruciate Ligament and Posterolateral Rotatory Instability of the Knee

Background

To determine if tibial positioning affects the external rotation of the tibia in a dial test for posterolateral rotatory instability combined with posterior cruciate ligament (PCL) injuries.

Methods

Between April 2007 and October 2007, 16 patients with a PCL tear and posterolateral rotatory instability were diagnosed using a dial test. The thigh-foot angle was measured at both 30° and 90° of knee flexion with an external rotation stress applied to the tibia in 2 different positions (reduction and posterior subluxation). The measurements were performed twice by 2 orthopedic surgeons.

Results

In posterior subluxation, the mean side-to-side difference in the thigh-foot angle was 11.56 ± 3.01° at 30° of knee flexion and 11.88 ± 4.03° at 90° of knee flexion. In the sequential dial test performed with the tibia reduced, the mean side-to-side difference was 15.94 ± 4.17° (p < 0.05) at 30° of knee flexion and 16.88 ± 4.42° (p = 0.001) at 90° of knee flexion. The mean tibial external rotation was 5.31 ± 2.86° and 6.87 ± 3.59° higher in the reduced position than in the posterior subluxation at both 30° and 90° of knee flexion.

Conclusions

In the dial test, reducing the tibia with an anterior force increases the ability of an examiner to detect posterolateral rotary instability of the knee combined with PCL injuries.     

The Huntington procedure: still a reasonable option for large tibial defects in paediatric patients

Background

Management of gap nonunion of tibia is technically difficult, time consuming, physically and psychologically demanding for the patient with unpredictable results. Various techniques have been described in literature for the treatment of gap nonunions, but each one has its own limitations.

Purpose

This study reports the outcomes of ipsilateral fibular transposition for reconstruction of tibial defects in paediatric age group.

Methods

We retrospectively reviewed records of 14 patients who underwent surgery for gap nonunion tibia with ipsilateral tibialization of fibula. Fibula is transferred to tibia as pedicle graft in two-staged procedure. Due to retained blood supply to one end of the transplant, the graft easily takes up and hypertrophies upon weight bearing over a period of time.

Results

Average time of radiographic union was 13.35 weeks. Guarded partial weight bearing was started at an average of 16.5 weeks with gradual progression to full weight bearing. The leg length discrepancy at final follow-up ranged from 0 to 7 cms with an average of 2.60 cms. Hypertrophy of tibialized fibula was observed in all patients, with 8 patients showed grafted fibula reaching the diameter of opposite tibia. On subjective assessment, 9 patients were highly satisfied, 4 patients were satisfied and one patient was dissatisfied with the procedure.

Conclusions

Huntington procedure is a simple, cost-effective and easy procedure for large tibial defects in paediatric patients which does not require any specialized team and implants, and can be performed in moderately equipped hospital. Leg length discrepancy may be addressed, after the transferred fibula is well developed.     

Stress Fracture of the Proximal Fibula in Military Recruits

Background

We wanted to report on stress fracture of the proximal fibula and to suggest the pathomechanism of this fracture.

Methods

Between April 2004 through April 2005, the military recruits who complained of leg pain during the 6 weeks basic training in the Republic of Korea Marine Corps education and training group were evaluated according to their clinical manifestations and plain radiographs.

Results

Twelve recruits of 635 recruits who complained leg pain were diagnosed as having fibular stress fracture. Eleven cases (10 recruits) appeared at the junction of the proximal and middle 1/3 of the fibula and 2 cases (2 recruits) were in the middle 1/3 of the fibula, as assessed radiologically. Tenderness was the most reliable clinical manifestation. All the fractures occurred after repetitive walking or jumping in a squatting position. Conservative treatments that included bed rest, immobilization and non-steroidal anti-inflammatory drugs administration according to the symptom severity were satisfactory.

Conclusions

Proximal fibular stress fracture is not rare in military recruits. The shearing force on the proximal fibula and the repetitive stress by walking or jumping in a squatting position contribute to the stress fracture of the proximal fibula.     

The use of external fixation combined with vacuum sealing drainage to treat open comminuted fractures of tibia in the Wenchuan earthquake

Purpose

The purpose of this study was to review the results of external fixation combined with vacuum sealing drainage (VSD) to treat patients who sustained tibial and fibular fractures in the Wenchuan earthquake.

Methods

We retrospectively analysed 179 cases (of which 85 were classified as Gustilo grade III) of open comminuted fracture of the tibia and fibula caused by the Wenchuan earthquake. The patients were followed up for an average of 15 months; detailed records were kept on their function and recovery.

Results

After caring for the life-threatening injuries; fractures were treated by external fixation, with VSD used on the surface or in the cavity of the wound after debridement. Antibiotics were administered on the basis of drug sensitivity test results. After the infection had been controlled and healthy granulation tissue had developed, the patients underwent secondary suture, free skin grafting, or skin flap transfer.

Conclusion

Good results can be achieved when external fixation combined with vacuum sealing drainage were used to treat open comminuted fractures of tibia and fibula in the Wenchuan earthquake.     

Fibular fixation as an adjuvant to tibial intramedullary nailing in the treatment of combined distal third tibia and fibula fractures: a biomechanical investigation

Objective

Distal third tibia fractures have classically been treated with standard plating, but intramedullary (IM) nailing has gained popularity. Owing to the lack of interference fit of the nail in the metaphyseal bone of the distal tibia, it may be beneficial to add rigid plating of the fibula to augment the overall stability of fracture fixation in this area. This study sought to assess the biomechanical effect of adding a fibular plate to standard IM nailing in the treatment of distal third tibia and fibula fractures.

Methods

Eight cadaveric tibia specimens were used. Tibial fixation consisted of a solid titanium nail locked with 3 screws distally and 2 proximally, and fibular fixation consisted of a 3.5 mm low-contact dynamic compression plate. A section of tibia and fibula was removed. Testing was accomplished with an MTS machine. Each leg was tested 3 times; with and without a fibular plate and with a repetition of the initial test condition. Vertical displacements were tested with an axial load up to 500 N, and angular rotation was tested with torques up to 5 N•m.

Results

The difference in axial rotation was the only statistically significant finding (p = 0.003), with fibular fixation resulting in 1.1° less rotation through the osteotomy site (17.96° v. 19.10°). Over 35% of this rotational displacement occurred at the nail–locking bolt interface with the application of small torsional forces.

Conclusion

Fibular plating in addition to tibial IM fixation of distal third tibia and fibula fractures leads to slightly increased resistance to torsional forces. This small improvement may not be clinically relevant.     

Pelvic massive allograft reconstruction after bone tumour resection

Purpose

The purpose of this report was to retrospectively review a series treated with pelvic tumour resection and massive allograft reconstruction, and determine survival of patients and implants, functional results and morbidity of surgical technique.

Methods

From 1999, 33 patients underwent pelvic tumour resection and massive allograft reconstruction. The mean age was 40 years (range, 14–72) and 29 patients had a primary malignant tumour. The resection involved the acetabular area in all but three patients.

Results

At a median follow-up of 33 months (range, two–143) four patients had local recurrence. The morbidity was high: five deep infections (15 %), requiring two allograft removal, six hip dislocations (18 %), eight sciatic nerve palsy (24 %), persistent in six cases, and two loosening of the acetabular component. Implant survival was 87.3 % at last follow up. The cumulative overall patient’s survival was 41.5 % at five and ten years. The average MSTS functional score was 70 % (range, 54–100 %) when the acetabulum was preserved while it was 61 % (30–100 %) in patients with acetabular resection.

Conclusion

In conclusion, pelvic allografts represent a valid option for reconstruction after resection of pelvic tumours but due to the associated morbidity, patients should be carefully selected.     

A rare cause of ‘drop foot’ in the pediatric age group: Proximal fibular osteochondroma a report of 5 cases

INTRODUCTION

The fibular nerve is the most frequent site of neural entrapment in the lower extremity and the third most common site in the body, following the median and ulnar nerves. The peroneal nerve is commonly injured upon trauma. Additionally, a dropped foot might be a symptom related to the central nervous system or spinal pathologies in pediatric patients. Entrapment of the peripheral nerve as an etiologic cause should be kept in mind and further analyzed in orthopedic surgery clinics.

PRESENTATION OF CASE

In this study, the evaluation and treatment results of five patients with no history of trauma, who underwent diagnostic procedures and treatment in various clinics (physical therapy and rehabilitation and neurosurgery), are reported. The patients underwent several treatments without diagnosis of the primary etiology. Upon initial consultation at our department, osteochondroma at the proximal fibula was detected after physical examination and radiologic assessment. During surgery, the peroneal nerve was dissected, starting from a level above the knee joint. Following nerve release, the osteochondroma was removed, including its cartilage cap. Consequently, recovery was observed in all five cases after surgery.

DISCUSSION

Many factors may cause non-traumatic neuropathies. However, due to their rare occurrence, lesions such as osteochondromas may be overlooked at non-orthopedic clinics. Nerve entrapment due to proximal fibular osteochondroma is rare. Surgical treatment planning plays a critical role in nerve entrapment cases.

CONCLUSION

Despite its frequent occurrence, a drop foot associated with peroneal nerve entrapment by an osteochondroma is not easily remembered and diagnosed. Especially in pediatric cases, inadequate clinical consultation and a lack of appropriate radiologic studies may result in a delay in diagnosing peroneal nerve lesions.     

Lateral tenodesis combined with anterior cruciate ligament reconstruction using a unique semitendinosus and gracilis transplant

Purpose

The aim of this study was to assess the anatomical results, functional results and the incidence of arthritis of a mixed intra- and extra-articular hamstring tendon based reconstruction for anterior instability of the knee.

Methods

This retrospective study consists of 100 knees in 99 patients (22 female and 77 male) operated upon between November 2003 and March 2006. The average age was 29.7 ± 10.4 years and the average interval between injury and surgery was 26.6 ± 41.8 months (2–240). In our technique, the semitendinosus and gracilis tendons were left attached to the tibia and by means of a lateral transcondylar tunnel posterior and inferior to the proximal attachment of the lateral collateral ligament were passed around the knee before being sutured to the fascia lata at the level of Gerdy’s tubercle.

Results

Sixty-eight knees were re-examined at an average follow-up of 76 ± 12 months. The average differential anterior drawer test at the last review was 2.5 ± 3.4 mm (p < 0.0001). Of the patients 75 % had a negative pivot shift test, 21 % a gliding test and 4 % a clear positive test (p < 0.0001); 84 % of patients had an International Knee Documentation Committee (IKDC) score rated A or B. The average IKDC subjective score was 90 ± 9 (60–100).

Conclusions

Mixed intra- and extra-articular reconstructions using hamstring grafts allow the knee to be stabilised in the sagittal plane and the rotatory instability to be controlled in the majority of cases. Only very minor progression of arthritic changes at an average 76 ± 12 months was seen.     

Fibula-related complications during bilateral tibial lengthening: 60 patients followed for mean 5 years

Background and purpose

Complications related to the fibula during distraction osteogenesis could cause malalignment. Most published studies have analyzed only migration of the fibula during lengthening, with few studies examining the effects of fibular complications.

Patients and methods

We retrospectively reviewed 120 segments (in 60 patients) between 2002 and 2009. All patients underwent bilateral tibial lengthening of more than 5 cm. The mean follow-up time was 4.9 (2.5–6.9) years.

Results

The average lengthening percentage was 34% (21–65). The ratio of mean fibular length to tibial length was 1.05 (0.91–1.11) preoperatively and 0.83 (0.65–0.95) postoperatively. The mean proximal fibular migration (PFM) was 15 (4–31) mm and mean distal fibular migration (DFM) was 9.7 (0–24) mm. Premature consolidation occurred in 10 segments, nonunion occurred in 12, and angulation of fibula occurred in 8 segments after lengthening. Valgus deformities of the knee occurred in 10 segments.

Interpretation

PFM induced valgus deformity of the knee, and premature consolidation of the fibula was associated with the distal migration of the proximal fibula. These mechanical malalignments could sometimes be serious enough to warrant surgical correction. Thus, during lengthening repeated radiographic examinations of the fibula are necessary to avoid complications.Extensive lower limb lengthening often introduces complications including genu varum, genu valgum, tibia vara, ankle varus, and ankle valgus which may require another surgical correction (Barreto et al. 2007).Soft tissue-resisting forces during the lengthening of bone are responsible for most of the complications. The resisting forces can be soft tissues, interosseus membrane, or bone itself in tibial distraction (Saleh et al. 2002, Hatzokos et al. 2004, Shyam et al. 2009). These resisting forces produce a drag effect on the fibula and hence there is decreased distraction, which is responsible for complications such as tibial axial deviation, and distraction at the proximal and distal tibiofibular joints. Several studies have found migration of the proximal and distal fibula during lengthening (Saleh et al. 2002, Hatzokos et al. 2004) but there is no clinical research regarding long-term outcome of the complications of the fibula itself such as premature consolidation, nonunion, and angulation. In an earlier study (Shyam et al. 2009), we reported increased knee laxity and valgus angulation of the tibia due to proximal fibular migration. In the present study of 120 lengthened tibial segments, we have investigated whether the various complications of the fibula affected the axial limb alignment and had a bearing on the joint-related complications.     

Intraosseous concentration and inhibitory effect of different intravenous cefazolin doses used in preoperative prophylaxis of total knee arthroplasty

Background

The aim of this study was to compare the intraosseous concentrations and the inhibitory effects on the growth of Staphylococcus aureus of 1 g versus 2 g of intravenous (IV) prophylactic cefazolin in total knee arthroplasty (TKA).

Materials and methods

Eighteen patients (21 knees) with primary knee osteoarthritis were divided into two groups receiving 1 g (12 patients: 14 knees) versus 2 g (six patients: seven knees) IV prophylactic cefazolin prior to the incision in TKA. Subchondral bone samples (proximal tibia, distal femur) were taken during the operation. These samples were analyzed for intraosseous concentration of cefazolin and their inhibitory effects on the growth of S. aureus, using high-performance liquid chromatography (HPLC) and agar disc diffusion bioassays.

Results

The mean intraosseous concentration in the 2 g dose group was significantly higher than in the 1 g dose group in the proximal tibia (p = 0.007) and distal femur (p = 0.016). There were no significant differences between the two groups in terms of mean inhibitory effects in the proximal tibia or distal femur (p > 0.05). No significant correlations were found between the intraosseous concentrations and inhibitory effects in the proximal tibia (r = 0.18, p = 0.52) and distal femur (r = −0.29, p = 0.30).

Conclusion

IV cefazolin at a dose of 2 g produced greater intraosseous concentrations overall than a dose of 1 g. However, the higher intraosseous concentrations did not correlate with higher inhibitory effects.

Level of evidence

Level III.     

Evaluation of a reconstruction reverse shoulder for tumour surgery and tribological comparision with an anatomical shoulder arthroplasty

Purpose

The functional results after reconstruction of the proximal humerus in tumour surgery are poor. Therefore, a reversed proximal humerus replacement was developed in our institution (MUTARS humerus inverse). A low degree of wear on the polyethylene is required because of the patients’ youth and demands on shoulder function. A special type of polyethylene with shock-absorbing properties has been developed to minimise polyethylene wear in the MUTARS inverse proximal humerus replacement. We compared the tribological properties of an anatomical shoulder prosthesis (CAPICA) with the new reversed proximal humerus replacement (MUTARS humerus inverse).

Methods

Both prostheses were tested up to 5 × 10⁶ cycles. Every millionth cycle the surface was inspected and a gravimetric measurement was performed. A measurement of surface roughness was done before testing and after 5 × 10⁶ cycles.

Results

In both prostheses after 5 × 10⁶ cycles there were no major defects, such as delamination, observed. In the reversed proximal humerus replacement abrasion of 28 mg/10⁶ cycles was detected. The mean abrasion of the anatomical prosthesis was 9.28 mg/ 10⁶ cycles.

Conclusion

The glenoid component of the first reversed humerus replacement (MUTARS humerus inverse) has wear properties comparable to those of normal reversed shoulder prostheses. This is important, as this type of prosthesis is used in young patients after resection of bone tumours, with a good functional outcome. It can, therefore, be expected that the revision rate due to wear will be as high as in patients with normal reversed shoulder prostheses.     

Knee flexion influences periprosthetic BMD measurement in the tibia: Suggestions for a reproducible clinical scan protocol

Background and purpose

The quality and quantity of bone is important for the success of joint prostheses and may be monitored by dual energy X-ray absorptiometry (DXA). Available protocols suggest that the knee should be positioned in full extension. This is not possible for most patients in the first days after surgery; however, deficits in extension normalize with rehabilitation. Individual knee flexion between the baseline and follow-up investigations may therefore be different. We investigated the sensitivity of bone mineral density (BMD) measurements to knee flexion in a phantom study and in patients. We suggest a protocol for clinical use.

Methods

2 phantom tibial bones with tibia components were secured in a clamp and BMD measurements were repeated 5 times at every 5° change in flexion from 0° to 20°. For clinical use, a soft foam positioner was produced, in which the lower leg could be placed in neutral rotation and with the knee in approximately 25° of flexion. The clinical repeatability was tested with double examinations in 38 patients. We investigated 3 regions of interest (ROIs) below the tibial plateau.

Results

In the phantom study, just 5° of flexion was found to change the measured mean BMD. The reproducibility of clinical measurements (coefficient of variation) in the 3 ROIs assessed ranged from 1.8% to 3.7% for the anteroposterior scans, and from 3.4% to 6.2% for the lateral scans.

Interpretation

Knee flexion does affect the measured periprosthetic tibial BMD, and knee flexion should be the same at all clinical follow-ups. The protocol and soft foam positioner that we suggest permit precise and reliable assessment of BMD in the proximal tibia and they can be used in clinical work.     

Epiphysis preserving resection of malignant proximal tibial tumours

Purpose

The purpose of the study was to evaluate the treatment of five patients with proximal tibial epiphysis preserving resection for malignant tumours of the tibia.

Method

Three patients suffered from Ewing sarcoma, two had osteosarcoma. The proximal level of the resection was in the line of the growth plate in four patients, and 2 cm below of the growth plate in one patient. The distal resection level was in the diaphysis, depending on the tumour border. The resected part of the tibia was substituted by both the ipsilateral and contralateral fibulas. The two fibulas were proximally built into the epiphysis, the contralateral, freely transplanted fibula was placed distally into the tibial diaphysis. The leg was fixed in an Ilizarov frame.

Results

The follow-up period was 4.9 years on average (range, 3.5–8 years). Neither local recurrence nor metastasis was noticed in patients with tibia tumour resection during the observation time. Proper fixation of the transplanted fibula with all of the patients, both proximal to the tibia epiphysis and distal to diaphysis, was experienced. The range of motion of the knee was 122° on the average. Two patients can walk without support and three can walk with an orthosis fully weight bearing. The limb shortening of the affected side was 2.6 cm on average (range,1.5–4.5 cm). In three patients the transplanted opposite side fibula has broken. In one patient, chronic osteomyelitis developed at the distal part of the transplanted fibula.

Conclusions

The difficulties of intercalary segment supplementation were present to a greater extent because of the small size of proximal epiphysis, but the preserved knee joint can produce better function for the patient in this limb-saving surgery.     

Management of juxta articular giant cell tumors around the knee by custom mega prosthetic arthroplasty

Background:

Juxtaarticular giant cell tumors around the knee are common and pose a special problem of reconstruction after tumor excision. This article analyzes the functional outcome after resection of juxtaarticular giant cell tumors around the knee and replacement by custom mega prosthetic arthroplasty.

Materials and Methods:

One hundred and forty-three patients with juxtaarticular giant cell tumors around the knee with mean age of 30.8 years (range 15 to 64 years) underwent resection and replacement by custom mega prosthetic arthroplasty during the period 1994 to 2005. Eighty-one patients were males and 62 were females. Fourteen patients were in Enneking Stage 2 while 129 patients were in Stage 3. Distal femur was involved in 87 patients and proximal tibia in 56 patients. Forty patients presented with pathological fracture at the time of diagnosis. The technique of sleeve resection of the quadriceps musculature was followed to achieve local clearance in distal femoral tumors, and for proximal tibial lesions resection of the tumor-bearing part and a medial gastronemius rotation flap was used routinely. The prosthesis used was a rotating hinge custom mega prosthesis manufactured locally.

Results:

The mean follow-up was 5.4 years (1.5 years to 11 years). Functional results were analyzed using Enneking criteria. Excellent results were obtained in 90 patients (62%) and 39 patients had good (27%) results. Periprosthetic fracture (8.3%) and infection (6.9%) were the most common complications followed by aseptic loosening (4.2%). Recurrence of lesion was found in only one patient (0.69%) who was managed with wide local excision.

Conclusion:

Custom mega prosthetic arthroplasty is effective in achieving the desired goals of reconstruction with good functional results and least complications in selected patients.     

Hoffa’s fat pad tumours: What do we know about them?

Purpose

We report on a group of patients with tumours in the Hoffa’s fat pad (HFP), their clinical presentation, histological type and treatment, including two synovial sarcomas with their clinical follow-up, which have not been described previously in the literature.

Methods

We performed a retrospective review of our prospectively collected database of 25 cases of HFP tumours with at least six months follow-up.

Results

The gender, age at presentation (over and under 16 years of age), clinical features, history of trauma, treatment chosen, and complications were recorded. The mean age of the patients was 32 years (three to 47). Six patients were under 16 years old. Pain was the most common symptom, present in 92 % (n = 23/25). The final diagnoses included 23 (92 %) benign tumours and two (8 %) malignant tumours. The most common benign tumour was pigmented villonodular synovitis (PVNS) (48 % n = 12). The two malignant tumours were synovial sarcomas and both presented in patients under 16 years old.

Conclusions

Hoffa’s fat pad tumours are an uncommon and rarely diagnosed group of lesions that can be misinterpreted as any knee pathology. Although the majority of HFP tumours are benign, malignant tumours should be considered in the differential diagnosis for the paediatric population.     

Quantification of the Effect of Vertical Bone Resection of the Medial Proximal Tibia for Achieving Soft Tissue Balancing in Total Knee Arthroplasty

Background

Degenerative osteoarthritis of the knee usually shows arthritic change in the medial tibiofemoral joint with severe varus deformity. In total knee arthroplasty (TKA), the medial release technique is often used for achieving mediolateral balancing. But, in a more severe varus knee, there are more difficult technical problems. Bony resection of the medial proximal tibia (MPT) as an alternative technique for achieving soft tissue balancing was assessed in terms of its effectiveness and possibility of quantification.

Methods

TKAs were performed in 78 knees (60 patients) with vertical bone resection of the MPT for soft tissue balancing from September 2011 to March 2013. During operation, the medial and lateral gaps were measured before and after the bony resection technique. First, the correlation between the measured thickness of the resected bone and the change in medial and lateral gaps was analyzed. Second, the possibility of quantification of each parameter was evaluated by linear regression and the coefficient ratio was obtained.

Results

A significant correlation was identified between alteration in the medial gap change in extension and the measured thickness of the vertically resected MPT (r = 0.695, p = 0.000). In the medial gap change in flexion, there was no statistical significance (r = 0.214, p = 0.059). When the MPT was resected at an average thickness of 8.25 ± 1.92 mm, the medial gap in extension was increased by 2.94 ± 0.87 mm. In simple linear regression, it was predictable that MPT resection at a thickness of 2.80 mm was required to increase the medial gap by 1.00 mm in knee extension.

Conclusions

The method of bone resection of the MPT can be considered effective with a predictable result for achieving soft tissue balancing in terms of quantification during TKA.     

Bone mineral density changes of the proximal tibia after revision total knee arthroplasty. A randomised study with the use of porous tantalum metaphyseal cones

Purpose

Forty patients were enrolled in a prospective randomised study using conventional method or “Trabecular Metal Cone” (TM Cone) (Zimmer inc., Warsaw, USA) for reconstruction of bone loss of the proximal tibia during revision total knee arthroplasty (rTKA). The aim was to evaluate changes in bone mineral density (BMD) at the proximal tibia.

Material and methods

Thirty-six patients [median 67 years (range: 40–85 years)] received rTKA with NexGen® (Zimmer Warsaw, USA) revision system. Knee Society´s Knee Scoring System and the Anderson Orthopaedic Research Institute (AORI) bone classification was used. Changes in BMD were measured by dual energy X-ray absorptiometry (DEXA).

Results

Knee and function score improved in both groups. No significant changes between the groups were found. Changes in BMD within the two groups were quite similar. Overall decreases in BMD of 0.1 - 5.4 % were found in both groups (ROI 1–6) postoperative to 12 months of follow-up, except that ROI 7 showed an increase in BMD (0.8 - 1.3 %). After 24 months of follow-up, an increase in BMD was found along the stem (ROI 2–5) of 1.9 - 6.3 % , with significant changes in the TM Cone Group (ROI 3, 4, 5) . No significant changes in BMD between the groups were found.

Conclusions

The bone remodelling pattern was almost the same in the two groups after two years.     

Is the Induced-membrane Technique Successful for Limb Reconstruction After Resecting Large Bone Tumors in Children?

Background

Resection of primary malignant tumors often creates large bony defects. In children, this creates reconstructive challenges, and many options have been described for limb salvage in this setting. Studies have supported the use of an induced-membrane technique after placement of a cement spacer to aid in restoration of bone anatomy.

Questions/purposes

We asked: (1) What complications are associated with the induced-membrane technique? (2) How often is bone healing achieved after resection greater than 15 cm using this technique? (3) What is the functional outcome of patients treated with this technique?

Methods

We performed a retrospective evaluation of eight patients with a mean age of 13.3 years (range, 11–17 years) treated for a malignant bone tumor between 2002 and 2012 at our centers. The primary malignant tumors involved the proximal humerus, femur, and tibia. All patients were treated using the induced-membrane technique after a resection with mean bone loss of 18 cm (range, 16–23 cm). The general indication for using the induced-membrane technique during this time was a large diaphyseal defect after resection of the tumor. In addition to using cancellous graft as with the original technique, in the current patients an autogenous nonvascularized fibula was used to enhance stability. The patients were assessed at the last followup using the Musculoskeletal Tumor Society (MSTS) scoring system. Mean followup was 47.1 months (range, 24–120 months), and none of the patients were lost to followup before 2 years.

Results

A total of four unplanned reoperations were performed in these eight patients. A fracture of the reconstruction occurred in three patients and all were treated successfully, two with surgery and one with immobilization. Bone fusion was obtained in all patients within 4 to 8 months (mean, 5.6 months) after the reconstruction. The mean healing index was 0.31 month/cm of reconstruction (range, 0.23–0.5 month/cm). At last followup, the mean MSTS score was 74% (range, 67%–80%).

Conclusions

Our findings suggest that the modified induced-membrane technique is a reasonable alternative to other limb reconstruction techniques for bone tumors in children and has the advantage of not requiring a bone bank or an expensive metal prosthesis. Although more patients will be needed to substantiate our findings, it has become a standard part of our arsenal in the treatment of large bone defects after resection of pediatric primitive bone tumors.

Level of Evidence

Level IV, therapeutic study.