Autografts containing bone marrow (BM) are current gold standard in the treatment of critical size bone defects, delayed union and bone nonunion defects. Although reaching unprecedented healing rates in bone reconstruction, the mode of action and cell-cell interactions of bone marrow mononuclear cell (BM-MNC) populations have not yet been described. BM-MNCs consist of a heterogeneous mixture of hematopoetic and non-hematopoetic lineage fractions. Cell culture in a 3D environment is necessary to reflect on the complex mix of these adherend and non-adherend cells in a physiologically relevant context. Therefore, the main aim of this approach was to establish conditions for a stable 3D BM-MNC culture to assess cellular responses on fracture healing strategies. BM samples were obtained from residual material after surgery with positive ethical vote and informed consent of the patients. BM-MNCs were isolated by density gradient centrifugation, and cellular composition was determined by flow cytometry to obtain unbiased data sets on contained cell populations. Collagen from rat tail and human fibrin was used to facilitate a 3D culture environment for the BM-MNCs over a period of three days. Effects on cellular composition that could improve the regenerative potential of BM-MNCs within the BM autograft were assessed using flow cytometry. Cell-cell-interactions were visualized using confocal microscopy over a period of 24 hours. Cell localization and interaction partners were characterized using immunofluorescence labeled paraffin sectioning. Main BM-MNC populations like Monocytes, Macrophages, T cells and endothelial progenitor cells were determined and could be conserved in 3D culture over a period of three days. The 3D cultures will be further treated with already clinically available reagents that lead to effects even within a short-term exposure to stimulate angiogenic, osteogenic or immunomodulatory properties. These measures will help to ease the translation from “bench to bedside” into an intraoperative protocol in the end

The clinical success of osteochondral autografts is heavily reliant on their mechanical stability, as grafts which protrude above or subside below the native cartilage can have a negative effect on the tribological properties of the joint [1]. Furthermore, high insertion forces have previously been shown to reduce chondrocyte viability [2]. Commercial grafting kits may include a dilation tool to increase the diameter of the recipient site prior to insertion. The aim of this study was to evaluate the influence of dilation on the primary stability of autografts.

Six human cadaveric femurs were studied. For each femur, four 8.5 × 8mm autografts were harvested from the trochlear groove and implanted into the femoral condyles using a Smith & Nephew Osteochondral grafting kit. Two grafts were implanted into dilated recipient sites (n=12) and two were implanted with no dilation (n=12). Insertion force was measured by partially inserting the graft and applying a load at a rate of 1 mm/min, until the graft was flush with the surrounding cartilage. Push-in force was measured by applying the same load, until the graft had subsided 4mm below congruency. Significance was taken as (p<0.05).

Average maximum insertion force of dilated grafts was significantly lower (p<0.001) than their non-dilated equivalent [28.2N & 176.7N respectively]. There was no significant difference between average maximum push-in force between the dilated and non-dilated groups [1062.8N & 1204.2N respectively].

This study demonstrated that significantly less force is required to insert dilated autografts, potentially minimising loss of chondrocyte viability. However, once inserted, the force required to displace the grafts below congruency remained similar, indicating a similar degree of graft stability between both groups.

Abstract

The optimal method of tibial fixation when using a hamstring tendon autograft in anterior cruciate ligament (ACL) reconstruction is unclear. This study aimed to compare the risk of revision ACL reconstruction between suspensory and interference devices on the tibial side.

Prospective data on primary ACL reconstructions recorded in the New Zealand ACL Registry between April 2014 and December 2019 were analyzed. Only patients with a hamstring tendon autograft fixed with a suspensory device on the femoral side were included. The rate of revision ACL reconstruction was compared between suspensory and interference devices on the tibial side. Univariate Chi-Square test and multivariate Cox regression was performed to compute hazard ratios (HR) and 95% confidence intervals (CI) with adjustment for age, gender, time-to-surgery, activity at the time of injury, number of graft strands and graft diameter.

6145 cases were analyzed, of which 59.6% were fixed with a suspensory device on the tibial side (n = 3662), 17.6% fixed with an interference screw with a sheath (n = 1079) and 22.8% fixed with an interference screw without a sheath (n = 1404). When compared to suspensory devices (revision rate = 3.4%), a higher risk of revision was observed when using an interference screw with a sheath (revision rate = 6.2%, adjusted HR = 2.05, 95% CI 1.20 – 3.52, p = 0.009) and without a sheath (revision rate = 4.6%, adjusted HR = 1.81, 95% CI 1.02 – 3.23, p = 0.044). The number of graft strands and a graft diameter of ≥8 mm did not influence the risk of revision.

When reconstructing the ACL with a hamstring tendon autograft, the use of an interference screw, with or without a sheath, on the tibial side has a higher risk of revision when compared to a suspensory device.

Abstract

Most previous studies investigating autograft options (quadriceps, hamstring, bone-patella-tendon-bone) in primary anterior cruciate ligament (ACL) reconstruction are confounded by concomitant knee injuries. This study aims to investigate the differences in patient reported outcome measures and revision rates for quadriceps tendon in comparison with hamstring tendon and bone-patella-tendon-bone autografts. We use a cohort of patients who have had primary ACL reconstruction without concomitant knee injuries.

All patients from the New Zealand ACL Registry who underwent a primary arthroscopic ACL reconstruction with minimum 2 year follow-up were considered for the study. Patients who had associated ipsilateral knee injuries, previous knee surgery, or open procedures were excluded. The primary outcome was Knee Injury and Osteoarthritis Outcome Score (KOOS) and MARX scores at 2 years post-surgery. Secondary outcomes were all-cause revision and time to revision with a total follow-up period of 8 years (time since inception of the registry).

2581 patients were included in the study; 1917 hamstring tendon, 557 bone-patella-tendon-bone, and 107 quadriceps tendon. At 2 years, no significant difference in MARX scores were found between the three groups (2y mean score; 7.36 hamstring, 7.85 bone-patella-tendon-bone, 8.05 quadriceps, P = 0.195). Further, no significant difference in KOOS scores were found between the three groups; with the exception of hamstring performing better than bone-patella-tendon-bone in the KOOS sports and recreation sub-score (2y mean score; 79.2 hamstring, 73.9 bone-patella-tendon-bone, P < 0.001). Similar revision rates were reported between all autograft groups (mean revision rate per 100 component years; 1.05 hamstring, 0.80 bone-patella-tendon-bone, 1.68 quadriceps, P = 0.083). Autograft revision rates were independent of age and gender variables.

Quadriceps tendon is a comparable autograft choice to the status quo for primary ACL reconstruction without concomitant knee injury. Further research is required to quantify the long-term outcomes for quadriceps tendon use.

The purpose of this investigation was to evaluate systematically the literature concerning biopsy, MRI signal to noise quotient (SNQ) and clinical outcomes in graft-maturity assessment after autograft anterior cruciate ligament reconstruction (ACLR) and their possible relationships. Methods: The systematic review was reported and conducted according to the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines. Studies through May 2019 evaluating methods of intra-articular ACL autograft maturity assessment were considered for inclusion. Eligible methods were histologic studies of biopsy specimens and conventional MRI studies reporting serial SNQ and/ or correlation with clinical parameters. Ten biopsy studies and 13 imaging studies, with a total of 706 patients, met the inclusion criteria. Biopsy studies show that graft remodeling undergoes an early healing phase, a phase of remodeling or proliferation and a ligamentization phase as an ongoing process even 1 year after surgery. Imaging studies showed an initial increase in SNQ, peaking at approximately 6 months, followed by a gradual decrease over time. There is no evident correlation between graft SNQ and knee stability outcome scores at the short- and long-term follow-up after ACLR. The remodeling of the graft is an ongoing process even 1 year after ACLR, based on human biopsy studies. MRI SNQ peaked at approximately 6 months, followed by a gradual decrease over time. Heterogeneity of the MRI methods and technical restrictions used in the current literature limit prediction of graft maturity and clinical and functional outcome measures by means of MRI graft SNQ after ACLR.

The aim of our study was to examine the outcome of ACL reconstruction by using four strand hamstring tendon autografts.

Material and Methods: the study included 44 patients (29 males,15 females;mean age 26;18–45 years). The diagnosis was based on clinical examination and imaging techniques. The operation was performed arthroscopically 4–62 weeks after the injury. The tendon was fixed in the tibia with an interference screw and in the femur with three different methods cross pin in 16 cases, transfix pin in 11 cases and Endo button in 17 cases.

Results: The mean follow up was 28 months (12–42). The mean Lysholm score was improved from 35–65 (mean 49) preoperativelly to 55–100 postoperativelly (mean 88).

5 patients had laxity > 3mm when compared to the healthy knee by using the KT-1000 arhthrometric testing. 2 of the latter patients complained of a feeling of knee joint instability which occurred due to inaccurate positioning of the femoral tunnel. In 2 cases the transfix pins were displaced and removed on the 4th and 15th post-operative month.

The tunnel expansion was measured by an X-Ray or a CT scan. The tibial tunnel expansion was 0–2.5mm (mean 1.2) or 18% and the femoral tunnel expansion was 0–3 mm (mean 1.4) or 26%. 8 patients reported mild pain which did not restrict their activities. A 5 degree loss of extension was noticed in one patient who continues physiotherapy.

28 of the above patients suffered also from a meniscal injury that was managed arthroscopically.

Conclusion: ACL reconstruction by using four strand hamstring tendon autografts is safe, highly successful with very few complications when proper graft preparation and accurate tunnel placement is achieved.

Limb salvage is the gold standard to treat sarcoma patients, but bone stock should be retained for the future, as many of these patients are young and active.

For this observational clinical study, 107 patients that presented with 108 malignant or locally aggressive benign bone tumours were treated by wide en-bloc resection of the affected bone, extracorporeal irradiation with 300 Gy to eradicate the tumour, and reimplantation of the bone as an orthotopic autograft. The irradiated bone was rigidly fixed to the remaining bone with classical intramedullary or extramedullary osteosynthesis material. We made a subdivision between intercalary, composite and osteoarticular grafts. The pelvis was considered a third separate entity, as it was considered both an intercalary and an osteoarticular graft when the acetabulum was involved.

The incidence of local recurrence with the use of an orthotopic autograft comprised the primary endpoint of this study. Secondary endpoints: preservation of bone stock with graft healing and evaluation of factors that determine preservation.

No local recurrences could be detected in the irradiated grafts. One local recurrence was detected in the surrounding soft tissue. At 5 years follow-up, graft healing occurred in 64% of cases, providing stable and lasting reconstruction. Eleven percent of the grafts had to be removed due to several incidents, but none could be proven significant. All patient subgroups displayed comparable results. Early infection appeared to be a significant determinant for the development of pseudarthrosis. Pelvic reconstructions showed a worse outcome. According to the results, guidelines for indications and surgical guidelines, such as rigid fixation and bridging of the graft, are proposed for using this technique. In general sarcoma resection, extracorporeal irradiation, and reimplantation provides a stable and lasting reconstruction with preservation of bone stock.

Structural bulk autografts restore the severe bone loss at primary hip arthroplasty in dysplastic hips and have shown to have good long term outcomes. There are only a few reports of revision arthroplasty for these sockets that fail eventually. We report on a series of such primary hips which underwent cemented revision of the socket for aseptic loosening and their outcomes.

A retrospective review was performed from our database to identify fifteen acetabular revisions after previous bulk autograft. The mean age at revision was 53.9 years (range 31–72.1). The mean duration between the primary and revision arthroplasty was 12.4 years (range 6.6 – 20.3). All procedures were done using trochanteric osteotomy and three hips also needed the femoral component revision. All fifteen hips needed re-bone grafting at the revision surgery to restore the new socket to the level of the true acetabulum. Of these ten hips had morsellised impaction allograft, and the remaining five also needing a structural bulk allograft.

Two sockets underwent re-revision at mean 7.5 years for aseptic loosening. One patient had a dislocation that was reduced closed. At a mean follow up of 5.7 years, one socket showed superior migration, but was stable and did not need further intervention. Two other sockets also showed radiological evidence of loosening, and are being closely monitored.

The medium term results of cemented acetabular revision in this younger age group are satisfactory, with repeat bone grafting being required to restore the true acetabular position. Though the primary arthroplasty with bulk bone graft recreates the acetabular bone stock, significant bone loss due to the mechanical loosening of the socket needs to be anticipated in revision surgery.

Introduction and purpose: Cortical strut autografts provide primary stability to resolve fractures or pseudoarthrosis associated with major bone loss, or fractures close to joint prostheses.

Materials and methods: We present 8 cases in which strut autografts were used: one pseudoarthrosis of the humerus, three periprosthetic fractures in TKR and four fractures associated with hip prosthesis surgery.

We resolved the humeral pseudoarthrosis with struts and a PCL plate plus cancellous tissue graft. For the periprosthetic fractures of the knee and hip we used revision prostheses with extension stems plus struts, held in place with cerclage wires or compression bands, with or without plates.

In all cases functional rehabilitation started early. The mean non-weight-bearing period for lower limbs was 10 weeks (8–12 months).

Results: Primary stability made it possible to begin rehabilitation early in all cases. Total consolidation of the grafts in a mean time of 5 months (4–7 months), with complete recovery of bone stock. Excellent functional outcome with full return to daily activity as before surgery.

Conclusions: The use of strut autografts associated with osteosynthesis and/or revision prosthesis implantation makes it possible to resolve cases that require a large amount of bone graft and provides sufficient primary stability for fast rehabilitation. The proper final consolidation of the grafts and complete recovery of bone stock provides stability with full guarantee of long-term success.

Bone loss can be treated in one of two general ways. Missing bone can be replaced either with bone graft applied to the host bone or augmentations attached to the revision implants. The ideal treatment of bone defects during revision TKR surgery: 1) makes immediate full weight bearing possible; 2) provides longterm support for the implants; 3) Restores original bone stock.

Bone grafts achieve these goals when the defects are CAVITARY. Therefore, bone grafts rather than metal augmentation devices are the surgical treatment of choice when these types of defects are encountered during revision TKR surgery.

Although bone grafts may achieve these goals when the defects are SEGMENTAL, the results are uncertain and more difficult to achieve. Metal augmentations make possible immediate full weight bearing and provide reliable long-term support for revision TKR implants. When these augments are made of Tantalulm, a metal with 80% porosity, the restoration of bone stock is also possible.

There are advantages and drawbacks to each approach. The advantages of bone grafts are that they: 1) restore bone stock; 2) are relatively inexpensive (especially if autogenous graft is used); 3) can be applied with relatively simple instrumentation; and 4) allow defects of a wide variety of sizes and shapes to be treated. The disadvantages of bone grafts are that they: 1) have limited application in large, segmental defects where structural support is necessary; 2) do not always unite predictably, particularly when the host bone is osteopenic or when angular deformities exist; 3) are shaped and inserted without the benefit of precise instrumentation; and 4) may require limited weight bearing or restricted activity for a period of time following surgery. The advantages of augmentation devices are that they: 1) can be manufactured in a wide variety of shapes and sizes; 2) provide immediate stable fixation; and 3) can be inserted using precise cutting instruments. Therefore, the indications for metal augmentation devices are: 1) uncontained defects (segmental) that require structural support for the knee implant; 2) knees with osteopenic bone or large angular defects; and 3) older patients in whom the importance of immediate mobilization and unrestricted weight-bearing is more important than the restoration of bone stock.

Introduction

The aim of this study is to evaluate the functional and oncological outcome of extracorporeally irradiated autografts as a method of pelvic reconstruction after internal hemipelvectomy.

The choice of graft for anterior cruciate ligament reconstruction remains controversial. A systematic review was performed to compare bone-patella tendon-bone and 4-strand hamstring grafts. Medline (1966 onwards), EMBASE (1980 onwards) and the Cochrane database were searched retrieving 6312 possible articles but only 6 studies fulfilled all the inclusion criteria. To be included, the study had to be prospective, randomised or quasi-randomised, comparing 4SHS and central third BPTB autografts, inserted using an arthroscopically assisted technique and have a minimum 2-year follow up for all patients. These studies recruited 526 patients and 475 were followed for at least 2 years with 235 patients receiving a bone-patella tendon-bone graft and 240 receiving a 4-strand hamstring graft. Overall, there was a greater chance of extension loss (p=0.007) and a trend towards increased patellofemoral joint pain (p=0.09) with a patella tendon graft. With a 4-strand hamstring graft there is a greater loss of hamstring power (p=0.008) and a trend towards an increased chance of a pivot shift > 1 (p=0.12). There was no difference between the 2 groups in terms of lachman testing, chance of returning to the same level of sport, clinical knee scores, graft ruptures or other complications.

The choice of graft for anterior cruciate ligament reconstruction remains controversial. A systematic review was performed to compare bone-patella tendon-bone and 4-strand hamstring grafts. Medline (1966 onwards), EMBASE (1980 onwards) and the Cochrane database were searched retrieving 6312 possible articles but only 6 studies fulfilled all the inclusion criteria. To be included, the study had to be prospective, randomised or quasirandomised, comparing 4SHS and central third BPTB autografts, inserted using an arthroscopically assisted technique and have a minimum 2-year follow up for all patients. These studies recruited 526 patients and 475 were followed for at least 2 years with 235 patients receiving a bone-patella tendon-bone graft and 240 receiving a 4-strand hamstring graft. Overall, there was a greater chance of extension loss (p=0.007) and a trend towards increased patellofemoral joint pain (p=0.09) with a patella tendon graft. With a 4-strand hamstring graft there is a greater loss of hamstring power (p=0.008) and a trend towards an increased chance of a pivot shift > 1 (p=0.12). There was no difference between the 2 groups in terms of lachman testing, chance of returning to the same level of sport, clinical knee scores, graft ruptures or other complications.

Introduction

Augmentation of spinal fusion using bone grafts is largely mediated by the osteoinductive potential of mesenchymal stem cells (MSC) that reside in cancellous bone. Iliac crest (IC) is a common autograft, but its use presents an increased risk for donor-site pain, morbidity and infection. Degenerative facet joints (FJ) harvested during facetectomy might servce as alternative local grafts. In this study, we conducted an intra-individual comparison of the osteogenic potential of MSC from both sources.

Osteochondral allografts (frozen uncontrolled, or cryo-protected with dimethyl sulfoxide) were transplanted into medial femoral condyles of eighteen sheep. Cores from the ipsilateral graft site served as autografts for the contralateral limb. Analysis of graft and host cancellous bone microarchitecture by μCT at three months post transplant demonstrated no significant differences among the treatment groups. Dramatic bone resorption at the graft–host interface, however, occurred in up to 1/3 of condyles from all treatment groups, including fresh autografts suggesting that factors other than donor source or tissue storage played an important role in the bone incorporation of osteochondral grafts.

The purpose of this study was to study the effect of different freezing protocols on periarticular cancellous bone architecture after osteochondral allograft transplantation.

There were no significant differences in graft or host cancellous bone architecture among the groups (autografts, frozen allografts, cryopreserved allografts). Dramatic resorption of graft bone in condyles from all treatment groups suggested that factors other than donor source or tissue storage played important roles during incorporation of osteochondral grafts.

Graft positioning, graft orientation, and recipient bed necrosis may play significant roles during incorporation of osteochondral graft bone.

Osteochondral allografts (10 mm diameter) were transplanted into medial femoral condyles of eighteen skeletally mature Suffolk ewes. Allografts were frozen (–80°C) without cryoprotectant (FROZ) or treated with dimethyl sulfoxide (cryoprotectant) and frozen (–80°C at 1°C · min⁻¹) (CRYO). Osteochondral cores removed from ipsilateral graft sites served as fresh autografts (AUTO) for the contralateral medial femoral condyles. Condyles were harvested at three months and scanned (micro computed tomography –μCT). Three dimensional μCT data of graft and host cancellous bone regions were analyzed for bone volume fraction, trabecular thickness, bone surface–volume ratio, and trabecular anisotropy. No morphological differences were found among treatment groups. Excessive bone resorption of graft and interface precluded analysis of some samples from each group (ALLO — 2/9, CRYO — 3/9, AUTO — 6/18). Dramatic bone loss did not correlate with poor graft orientation, placement, infection, or recipient–bed necrosis, but a combination of these factors may contribute to excessive cancellous bone resorption in osteochondral grafts.

Funding: Medical Research Council of Canada, Canadian Institutes of Health Research, No commercial funding

Please contact author for figures and/or diagrams.

Purpose: The optimal autograft choice for ACL reconstruction remains controversial. Twelve recently published reviews comparing Patellar Tendon (PT) to Hamstring Tendon (HT) autografts in ACL reconstruction vary in their methodology, quality and application of sensitivity analyses. The present review and meta-analysis follows the rigorous methodology of the Cochrane Collaboration of Systematic Reviews and includes more recent trials that utilize modern surgical techniques and concealed randomization.

Method: Randomized Clinical Trials (RCT) and Quasi-randomized Trials (QRCT) with a minimum 2-year follow-up comparing PT with HT autografts in patients undergoing primary ACL reconstruction were included. Non-English articles were professionally translated. Four electronic databases were searched from 1969-present. Bibliographies and proceedings of major orthopaedic meetings were handsearched. Two teams of investigators independently reviewed all citations, selected relevant studies, extracted the data and assigned quality scores. Consensus was achieved within and between each team for all stages of the review process.

Results: Three hundred and twenty-six citations were originally identified with the search criteria. Following rigorous review, 26 relevant studies were identified. Nine were excluded due to missing information, inadequate follow-up, ongoing trials or low quality scores, leaving 17 studies included in the final analysis. Outcomes related to stability (Lachman test, instrumented laxity, and pivot shift) showed trends towards improved stability with PT reconstruction. When QRCTs were excluded there was a significant difference favoring PT reconstructions only with respect to the pivot shift test. All other outcomes were similar between the PT and HT reconstructions including IKDC categories, anterior knee pain (trend in favor of HT), re-rupture rate, and activity levels. No information was available to distinguish between the outcome of acute and chronic reconstructions, long term information or validated patient based outcomes.

Conclusion: The current literature fails to demonstrate significant differences in multiple outcomes comparing PT to HT reconstruction of the ACL. The overall quality of trials is questionable and fails to use validated patient based outcomes or sufficiently long-term results to assess the development of osteoarthritis.

The purpose of this study was to establish the return of function to an unstable knee following stabilization of the anterior deficient cruciate ligament.

15 consecutive cases of chronic anterior cruciate ligament rupture with instability were studied prior to stabilization by patellar bone-tendon-bone autograph, and again at three months post-operation and at one year post stabilization. There were two women and thirteen men in this study. All operations were performed by one of the authors (John Fleetcroft).

Peak torque, total work and average power were studied at 90°/sec and 120°/sec.

Three patients had unusually low contralateral flexor power at 120°/sec pre-operatively, these measurements were excluded from the 120°/sec results.

Our findings show an initial decrease of strength three months postoperatively; on the extensors more than on the flexors.The flexors recovered faster than the extensors.

Extensor function showed a deficit of 13% at both speeds pre-operatively. Three months following surgery this has increased to an average of 33.7% at 90°/sec and 22.8% at 120°/sec. At one year the deficit had decreased dramatically to 2.2% at 90°/sec and 0.14% at 120°/sec.

Flexor function at 90°/sec showed a deficit of 6.4% pre-operatively, 15% at three months and 1.7% at one year. At 120°/sec, pre-operative flexor deficit was 3.1%, +0.16% at three months and +4.4% at one year.

These tests demonstrate the return of function to unstable cruciate deficient knees, an important observation for those wishing to return to sport.

Defects of the anterior cruciate ligament have been treated surgically with intra- and extra-articular procedures since several decades, either as direct repair or using autografts of the hamstring or patella tendon in open or arthroscopic operations. On the other hand there are studies about successful results of conservative treatment available, too.

Casteleyn et al (1) reported about the follow up of at least five years (mean 8.5 years) of 109 patients which excluded professional and high level athletes. The evaluation of their symptoms with an IKDC score showed 23% in grade A and 50% in grade B out of four possible grades with an incidence of 5.4% secondary ACL surgery.

In an editorial article about anterior cruciate ligament reconstruction Dandy et al (2) reviewed the results of several studies about intra- and extra-articular procedures, which examined pivot-shift and restriction of activity.

Johnson et al (3) found in 87 patients with bone-patellar tendon-bone reconstruction and a mean follow up of 7.9 years 26% positive pivot shift and 25% of the patients had unrestricted activity. Sandberg et al (4) reviewed a similar group of 89 patients after seven years with 11% positive pivot-shift and 24% unrestricted activity.

In comparison to these results extra-articular procedures show a higher incidence of pivot-shift and lower levels of unrestricted activity; Odensten et al (5) report 59% clinical instability four years after Ellison procedure and 39% positive pivot-shift with only 44% unrestricted sport activity at six years after MacIntosh operation.

Over the last years extra-articular procedures were abandoned in favor for intra-articular operations.

Today bone-patellar tendon-bone grafts are widely used for these repairs.

Clancy et al (6) and Butler et al (7) have shown in animal studies a decrease of strength and mechanical properties postoperatively during an initial period of revascularisation and remodelling.

Grontvedt et al (8) look at these properties in their study about the effects of the use of a ligament augmentation device by isokinetic testing on a Biodex™ system. They measured peak torque and total work and found a deficit in the quadriceps strength in comparison to the uninjured knee of 25% at six months, 15% at one year and 10% at two years. The hamstrings improved to equal levels already after six months.

The aim of our study was to assess the mechanical properties torque, total work and average power of the hamstrings and quadriceps in order to evaluate the progress of the patients postoperatively including the above mentioned initial decrease in strength. The testing was performed with a Cybex™ machine preoperatively as well as three and twelve months postoperatively.

We tested patients who had a bone-tendon-bone anterior cruciate ligament reconstruction performed between March 1998 and January 1999. It was only a limited time window available for this study and therefore we could conduct the tests only on 15 consecutive patients. We tested two women and 13 men. Their mean age was 38.4 years (21 to 50). Injuries of the anterior cruciate ligament were confirmed by both clinical and arthroscopic examination. Indications were clinical instability, pain and / or swelling during sport or other physical activity and / or other relevant history (knee gives way). All the operations were arthroscopic assisted procedures. They were performed by only one surgeon (J P Fleetcroft). The graft was obtained from the middle third of the patellar tendon and fixed with Acufex™ interference screws.

The isokinetic tests were performed preoperatively, then three months postoperatively and one year postoperatively. The following parameter were obtained for both flexors and extensors at two speeds (90°/sec and 120°/sec): peak torque, total work and average power. At the preoperative test both injured and contralateral knees were tested, at three months and one year only the involved knee. The figures of the uninvolved knee were used as references to calculate mean deficit / progress percentages for the operated side during the course of the study.

Three patients (number 2, 6 and 14) showed at the preoperative measurements unusually low strength at the 120°/sec tests of the flexors of their uninjured knees. The figures of the uninjured knees had to be used as references in the evaluation of progress / deficits of the injured and operated knees. Therefore all calculated results of those three patients became unrealistically high and did not represent true values. As the mechanical properties of the uninjured knees were otherwise of no interest for this study we decided to exclude these patients from the 120°/sec flexor tests.

Preoperatively the extensors showed a deficit of strength (average of peak torque, total work and average power) at both speeds of 13%. This deficit worsened at three months to 33.7% at 90°/sec and 22.8% at 120°/sec. After one year strength had improved nearly to the preoperative level with a deficit of 2.2% at 90°/sec and 0.14% at 120°/sec.

Flexors: The flexors showed smaller deficits than the extensors. Preoperative figures show deficits of 6.4% at 90°/sec and 3.1% at 120°/sec. At three months the deficit at 90°/sec worsened to 15% but at 120°/sec it improved to the level of the unoperated leg (+0.16%). After one year the strength was at both speeds better than at the unoperated leg (+1.7% at 90°/sec and +4.4% at 120°/sec). The detailed deficit / progress figures for all the measured properties of our study are shown in the tables below.

Table 1 Mean deficit / progress [%]; PT = peak torque, TW = total work, Pow = average power

Table 2 Deficit / progress [%] of strength (average of peak torque, total work, average power)

The strength deficits which resulted from the anterior cruciate ligament defect improved significantly. In both muscle groups and at both test speeds the average strength of the operated knee was after 12 months at about the same level as the uninjured leg. As the flexors are to a lesser extent effected by the operation than the extensors they recovered faster; similar to the findings of Grontvedt et al (8).

The flexors showed at both speeds slightly better results than the uninvolved knee and only the extensors had still a small deficit of 0.147% (120°/sec) and 2.21% (90°/sec) in comparison to the uninjured knee after 12 months.

Further could be shown that apart from flexors at 120°/sec an initial decrease in strength occurred at the three months measurements (as also reported in [6] and [7]).

Grontvedt et al ( 8) still report about 25% weakness of the extensors after six months. In our study already at three months all groups apart from the extensors at 90°/sec (−33.7%) have results better than this (−22.8%, −15.04%, +0.17%). Grontvedt’s study shows 15% deficit after one year and 10% after two years. In comparison to this we could demonstrate nearly normal results (−2.2%, −0.14%, +1.7%, +4.4%) after 12 months. As the test speed influences the results especially during the initial period of decreased strength and Grontvedts study tested at 60 and 240°/sec this might be one reason for the different results.

The overall figures for the patients’ progress are satisfactory. They demonstrate the return of function to an initially unstable cruciate deficient knee.

We would suggest further research into the details of the initial weakness during the first postoperative months as this might have implications for physiotherapy and rehabilitation as well as surgical technique and devices.

Fibula autograft reconstruction, both vascularised (v) and non-vascularised (nv), has been established as a standard method in limb salvage surgery of bone and soft tissue tumours of the extremities. This study retrospectively analyses the results of fibula autograft procedures in general and in relation to vascular reconstruction or simple bone grafting.

Since the implementation of the Vienna Tumour Registry in 1969, 26 vascularised and 27 non-vascularised fibula transfers have been performed at our institution in 53 patients, 26 males and 27 females with an average age of 21 years (range 4 to 62 years). Indications included osteosarcoma in 18, Ewing’s Sarcoma in 15, adamantinoma in 5, leiomyosarcoma in 3 and others in 12. Thirty patients were operated for reconstruction of the tibia (8v/22 nv), 7 for the femur (6v/1nv), 7 for defects of the forearm (4v/3nv), 5 for metarsal defects (all v), 3 for the humerus (1v/2nv) and one patient was treated for a pelvic defect (nv).

Average follow-up was 63 months (range 2 to 259 months). 43 patients showed successful primary bony union of the autograft. In 12 cases pseudarthrosis indicated further surgical revision, 9 of these patients were primarily reconstructed by use of a nv autograft. 4 patients, 2 with v and 2 with nv reconstruction, suffered a fracture of the transplant and were operated for secondary osteosynthesis. 10 patients with v bone graft developed wound healing disturbances which led to surgery, 2 patients with nv grafts suffered such complications. In 2 patients recurrent infection of a nv and a v fibula transfer led to the implantation of a modular tumour prostheses or amputation, retrospectively. Function of all patients with primary bone healing was rated satisfactory.

The use of fibula autograft in limb-salvage surgery under oncological conditions allows biological reconstruction with good functional outcome, especially when primary bone healing is achieved. Vascularised bone grafting seems to have a better outcome in terms of primary bone healing than simple fibula bone grafting, and thus represents a feasible choice in the reconstruction of bone defects from tumour resection.