Use of distal femoral osteoarticular allografts in limb salvage surgery

BACKGROUND

As diagnostic and therapeutic techniques improve, patients with a musculoskeletal sarcoma should expect longer survival, fewer complications and side effects, and an improved quality of life. Functional longevity of the reconstruction after resection of the tumor becomes a major concern, especially in young and physically active patients. The purpose of this study was to analyze the mid-term and long-term survival of reconstructions with a distal femoral osteoarticular allograft in a series of patients.

METHODS

We retrospectively reviewed the results of eighty reconstructions with a distal femoral osteoarticular allograft following resection of a bone tumor in seventy-six patients. The mean duration of follow-up was eighty-two months. The rates of survival of the allograft and the joint surface were estimated with use of the Kaplan-Meier method. Cox regression analysis was performed to determine whether age, gender, the percentage of the femur that had been resected, and the use of chemotherapy were independent prognostic factors. Functional and radiographic results were documented according to the Musculoskeletal Tumor Society scoring system at the time of the latest follow-up.

RESULTS

Five patients were lost to follow-up, leaving seventy-five allografts in seventy-one patients available for study. Thirteen patients (thirteen allografts) died of tumor-related causes without allograft failure before a two-year radiographic follow-up could be performed. Of the remaining sixty-two allografts, fourteen failed: six failed as a result of infection; four, because of local recurrence; one, because of massive resorption; and three, as a result of fracture. At the time of final follow-up, at a mean of 125 months, forty-eight allografts were still in place. The overall rate of allograft survival was 78% at both five and ten years, and the rate of allograft survival without the need for resurfacing with a knee prosthesis was 71% at both five and ten years. With the numbers available, age, gender, the percentage of the femur that had been resected, and the use of chemotherapy were not found to have a significant effect on the overall allograft survival rates. The patients who retained the original allograft had good or excellent functional and radiographic results.

CONCLUSIONS

The life expectancy for most patients with a highly aggressive or malignant tumor in the distal part of the femur is now several decades. In this study, we found a high rate of survival of distal femoral allograft reconstructions at both five and ten years.

Excessive tibial rotation during high-demand activities is not restored by anterior cruciate ligament reconstruction

PURPOSE

Recent in vitro research has suggested that anterior cruciate ligament (ACL) reconstruction does not restore control of tibial rotation. The purpose of this study was to explore these findings in vivo and investigate rotational knee stability during landing and subsequent pivoting. Such an activity places higher demands on the knee, almost similar to those found during high-level sports.

TYPE OF STUDY

Case control series study.

METHODS

We assessed 11 patients who had undergone ACL reconstruction with the same arthroscopic technique using a bone-patellar tendon-bone graft, 11 ACL-deficient subjects who had sustained the injury more than 1 year prior to testing, and 11 matched controls. Kinematic data were collected (50 Hz) with a 6-camera optoelectronic system while the subjects performed the following task: they jumped off a 40-cm platform and landed on the ground. After foot contact, the subjects were instructed to pivot at 90 degrees and walk away from the platform. The evaluation period was identified from initial foot contact with the ground with both legs, included the pivoting of the ipsilateral leg, and was completed on touchdown of the contralateral leg.

RESULTS

Significant differences were found between the reconstructed leg of the ACL group and the healthy control, and between the deficient leg of the ACL-deficient group and the healthy control. We also found no significant differences between the deficient leg of the ACL-deficient group and the reconstructed leg of the ACL reconstructed group.

CONCLUSIONS

It was concluded that, under high-stress activities, ACL reconstruction may not restore tibial rotation to the previous physiological level, even though anterior tibial translation is restored. Future research on ACL reconstruction should focus on the development of new surgical procedures and/or grafts to address this problem.

LEVEL OF EVIDENCE

Level III.

Anatomically oriented anterior cruciate ligament reconstruction with a bone-patellar tendon-bone graft via rectangular socket and tunnel: a snug-fit and impingement-free grafting technique

An anterior cruciate ligament (ACL) reconstruction technique is described to place bone-patellar tendon-bone (BPTB) graft in an anatomically oriented fashion to mimic the 2 bundles of the normal ACL, based on the concept of twin tunnel ACL reconstruction, to maximize the graft-tunnel interface. In this technique, the attached bone plug is introduced into a rectangular femoral socket via a halfway rectangular tibial tunnel for the anterior portion of the graft to function as the anteromedial bundle and for its posterior portion to behave as the posterolateral bundle. A snug fitting of the graft is achieved not only at the femoral socket, but also in the tibial tunnel.

Graft length changes in the bi-socket anterior cruciate ligament reconstruction: comparison between isometric and anatomic femoral tunnel placement

PURPOSE

To compare the length change of grafts in bi-socket anterior cruciate ligament (ACL) reconstruction between isometric and anatomic placement.

TYPE OF STUDY

Case series.

METHODS

The subjects were 110 knees of 110 patients with a mean age of 27 years. All knees were reconstructed using multistranded autogenous semitendinosus tendon and the bi-socket procedure. Of those, 43 knees were reconstructed in the isometric position, around the isometric point (group I) and the remaining 67 in the anatomic position, mimicking the anatomic footprint of ACL (group II). Grouping was performed based on the femoral socket position. Each femoral socket for the anterior medial graft (AMG) and the posterolateral graft (PLG) for the left knee was positioned at 1 o'clock and 2 o'clock to 2:30 in group I, or 2 o'clock and 3 o'clock in group II in the posterior border of the notch. Their positioning for the right knee was at 11 o'clock and 9:30 to 10 o'clock in group I, or 10 o'clock and 9 o'clock in group II. The length changes of grafts were intraoperatively measured while extending the knee from 120 degrees to full extension, using a commercially available isometric positioner. The Student t test was used for statistical analysis.

RESULTS

All the grafts showed the pattern of elongation approaching extension. The length change of AMG and PLG was 1.3+/-0.6 mm and 2.2+/-1.0 mm in the group I, 1.4+/-0.7 mm and 2.5+/-0.9 mm in the group II, respectively. There was no statistically significant difference in the values of AMG (P = .51) and PLG (P = .074) between the 2 groups.

CONCLUSIONS

The length change of ACL grafts placed in the anatomic position was not significantly different from that positioned in the isometric position.

LEVEL OF EVIDENCE

Level IV, case series.

Anterior cruciate ligament reconstruction with hamstring tendons and cross-pin femoral fixation compared with patellar tendon autografts

PURPOSE

To investigate the outcome of arthroscopic anterior cruciate ligament (ACL) reconstruction with hamstring autograft using femoral cross-pin fixation compared with patellar tendon autografts.

TYPE OF STUDY

Matched retrospective cohort.

METHODS

Twenty-one patients who underwent ACL reconstruction with hamstring autograft and femoral cross-pin fixation were evaluated at an average of 16.4 months postoperatively. Subjective data were collected using the International Knee Documentation Committee (IKDC) and the Cincinnati Knee Scale. Objective data included a comprehensive knee examination, plain radiographs, and KT-1000 measurements. The results were compared with 19 matched patients who had previously undergone ACL reconstruction using patellar tendon autograft.

RESULTS

The average KT-1000 maximal manual side-to-side difference was 1.63 +/- 0.68 mm. Eighty-six percent of IKDC scores were normal or nearly normal. The average overall Cincinnati Knee Scale subjective symptom rating was 8.7 +/- 1.2. There was no significant difference in subjective or objective data between the 2 groups.

CONCLUSIONS

ACL reconstruction using femoral cross-pin fixation is a reliable technique showing outcomes comparable to other established methods of fixation.

LEVEL OF EVIDENCE

Level IV, case series.

Osteochondral autograft transplantation for osteochondritis dissecans of the capitellum in nonthrowing athletes

In this report, we present the cases of 3 nonthrowing athletes with osteochondritis dissecans of the capitellum. Preoperatively, they complained of elbow pain during rhythmic gymnastics, table tennis, and basketball, respectively. Magnetic resonance imaging showed a completely separated osteochondral fragment or a full-thickness cartilage defect. All 3 patients were treated with transplantation of an osteochondral autograft harvested from the lateral femoral condyle. They returned fully to their sports activities within 6 months of surgery. The continuity of the cartilage layer between the osteochondral graft and the capitellum was shown on magnetic resonance images taken at 12 months postoperatively. We believe that osteochondral autograft transplantation provides successful results for nonthrowing athletes with end-stage osteochondritis dissecans of the capitellum.

Extensor mechanism disruption after contralateral middle third patellar tendon harvest for anterior cruciate ligament revision reconstruction

The contralateral central third patellar tendon autograft is a reliable graft choice for revision, and recently, for primary reconstruction of the anterior cruciate ligament (ACL). We report 2 complications including a lateral third tibial tuberosity fracture and a distal patellar tendon avulsion with contralateral patellar tendon autograft with disruption of the extensor mechanism of the donor knee. A patient sustained a lateral tibial tuberosity fracture of the donor knee and underwent open reduction and internal fixation. At 1-year follow-up, she had no extensor lag and full range of motion. Another patient sustained a distal patellar tendon avulsion of the donor knee and underwent primary repair. Three years postoperatively, she had a full range of motion and no extensor lag. Although contralateral middle third patellar tendon autograft for primary and revision ACL reconstruction is established in the literature, extensor mechanism complications can occur. Technical considerations are important to avoid weakening the remaining patellar tendon insertion. Postoperative nerve blocks or local anesthetics may alter pain feedback for regulation of weight bearing and contribute to overload of the donor knee.

A meta-analysis of stability after anterior cruciate ligament reconstruction as a function of hamstring versus patellar tendon graft and fixation type

PURPOSE

Four-strand hamstring graft (4HS) is stronger than 10-mm bone-patellar tendon-bone graft (BPTB) and has equal tunnel pullout strength, but is believed by some to produce lower rates of stability after anterior cruciate ligament reconstruction (ACLR). Our purpose was to test the hypothesis that 4HS ACLR with modern fixation would produce equal or greater stability than BPTB ACLR.

TYPE OF STUDY

Meta-analysis.

METHODS

A computer search was used to find all published reports of ACLR series using HS and/or BPTB. Inclusion criteria were minimum 24-month follow-up, stratified presentation of arthrometric stability data, and at least 30-lb arthrometric testing force. Twenty-four 4HS, 8 2-strand hamstring (2HS), and 32 BPTB series met these criteria and were subdivided into groups according to fixation type. We used the International Knee Documentation Committee classification of a side-to-side instrumented Lachman test difference of < or = 2 mm as normal stability, and > 5 mm difference as abnormal stability. Series with at least 80% normal and at most 3% abnormal stability were designated as high-stability. Meta-analytic methods were used to determine group level differences.

RESULTS

Total 4HS had a higher normal stability rate than total BPTB: 77% versus 66%, P < .001; and lower abnormal stability: 4.4% versus 5.9%, P = .029. The 4HS ACLR using the EndoButton (Smith & Nephew Endoscopy, Andover, MA) and second-generation tibial fixation (EB2-4HS) had higher normal stability (80%) and lower abnormal stability (1.7%) than all other subgroups, including BPTB with 2 interference screws (70% normal, 5.0% abnormal) P < .001; 84% of the series in the EB2-4HS group were high-stability series. No more than 33% of the series from any other group were high-stability.

CONCLUSIONS

The recent literature would suggest that 4HS ACLR produces higher stability rates than BPTB, that 4HS stability rates are fixation dependent, that aperture fixation offers no stability advantage, and that EndoButton with second-generation tibial fixation produces consistently high stability rates.

LEVEL OF EVIDENCE

Level IV.

Management of big osteochondral defects of the knee using osteochondral allografts with the MEGA-OATS technique

Treatment of osteochondral defects in weight-bearing areas of the knee, especially when they are sizeable and involve considerable subchondral bone loss, is a challenging problem. We report our experience on the use of osteochondral allografts with the MEGA-OATS technique in the management of large osteochondral defects of the knee in young patients. Five patients (3 male and 2 female) were included in this study; their age ranged from 22 to 41 years and the mean size of the defect covered was 30 x 30 mm. They were followed for a minimum of 2.5 years (mean: 32.8 months, range 30-36). An age- and size-matched fresh frozen, non-irradiated distal femoral allograft was used to obtain the donor plug, which was then inserted in the recipient area in a press-fit fashion. Patients' Lysholm knee score increased from 37.8 pre-operatively to 73.8 post-operatively. Tegner activity score increased in all five patients; it improved from a mean of 2 pre-operatively (range 1-3) to 4 post-operatively (range 2-7). Four out of five patients returned to work and three went back to sporting activities. With this technique one can cover sizeable osteochondral defects, and compensate for significant subchondral bone loss, while accurate reconstruction of the curvature of the femoral condyle is allowed. We believe that it is a viable salvage option in young patients with big osteochondral defects of the knee. It offers very satisfactory functional results and does not compromise patients' future options.

[Comparison of total hip replacement and transplantation of vascularized bone graft in treating late ischemic necrosis of the femoral head]

OBJECTIVE

To compare the effects and indications of total hip replacement (THR) and transplantation of vascularized bone graft in treating late ischemic necrosis of the femoral head.

METHODS

From March 1986 to March 1993, 81 patients with late ischemic necrosis underwent treatment. Of 81 patients, 59 patients who suffered in unilateral hip were divided into 2 groups: 26 underwent total hip replacement and 33 underwent transplantation of vascularized bone graft. There was no significant difference in the Harris-scores of the two groups before operations (P>0.05). The Harris hip scores were compared between different ages (<30 years, 31-50 years, and >51 years) in two groups.

RESULTS

The follow-up ranged from 10 years and 3 months to 16 years and 5 months (15 years and two months on average). The changes of Harris-scores of the two groups after operations had significant difference in initial stage (P<0. 05), but had no significant difference in the long term (P>0.05). The change of Harris-scores of patients who underwent total hip replacement had no significant difference between different ages (P>0.05), but that of patients who underwent transplantation of vascularized bone graft had significant difference between different ages (P<0.05). Both groups had satisfactory effects in treating late ischemic necrosis of the femoral head.

CONCLUSION

Both methods are effective in treating late ischemic necrosis of the femoral head. Total hip replacement can be more effective in senior patients. Transplantation of vascularized bone can be more effective in young patients.

The structural allograft composite in revision total knee arthroplasty

Although morselized cancellous autograft or allograft has been shown to be highly successful for management of smaller cavitary defects in revision TKA, structural allografts often are required for large, contained, or uncontained osseous defects. Early clinical results of revision TKA using structural allografts have been encouraging with high allograft-host union rates, as long as adequate fixation is obtained. The use of intramedullary stems with sufficient length to engage diaphyseal bone is recommended to lessen load transmission to the structural allograft and to reduce the risk of late allograft collapse or fracture. Extensive preoperative planning, meticulous operative technique, and an extended period of postoperative rehabilitation are required for optimal

Computerized matching of autologous femoral grafts for the treatment of medial talar osteochondral defects

BACKGROUND

Cored autologous graft from the distal ipsilateral femur has been used to fill osteochondral defects in the talus. There are no studies that compare the articular morphology of potential donor sites on the distal femur with recipient sites on the talus.

METHODS

Using coronal MRI of the talus and distal femur of five matched cadaver, computer reconstructions of the articular surfaces were prepared. From these, six 10-mm in diameter donor sites from the nonweightbearing surfaces of the medial and lateral aspects of the femoral condyles were matched to three recipient sites on the anterior, middle, and posterior aspects of the corresponding medial talus using customized computer software that minimized differences between the articular surfaces of the graft and the talus. After matching the femoral to the talar graft, the average and maximal distances between the surfaces (surface contour) and the average and maximal distances of the offset at the outer 1 mm of the graft periphery (step-off) were determined.

RESULTS

For all graft combinations, the average step-off was 0.24 +/- 0.03 mm and the maximum 0.60 mm. The average surface contour was 0.32 +/- 0.04 mm and the maximum was 1.16 mm. In all cases, the best donor site was from the superolateral femur for any medial talar lesion.

CONCLUSION

In this study of grafts from the femoral condyles, the superolateral femur was the optimal location for an osteochondral graft for any medial talar lesion.

A prospective randomized clinical study of mosaic osteochondral autologous transplantation versus microfracture for the treatment of osteochondral defects in the knee joint in young athletes

PURPOSE

The purpose of this study was to compare the outcomes of mosaic-type osteochondral autologous transplantation (OAT) and microfracture (MF) procedures for the treatment of the articular cartilage defects of the knee joint in young active athletes.

TYPE OF STUDY

Prospective randomized clinical study.

METHODS

Between 1998 and 2002, a total of 60 athletes with a mean age of 24.3 years (range, 15 to 40 years) and with a symptomatic lesion of the articular cartilage in the knee were randomized to undergo either an OAT or an MF procedure. Only those athletes playing in competitive sports at regional or national levels were included in the study. Fifty-seven athletes (95%) were available for a follow-up. There were 28 athletes in the OAT group and 29 athletes in the MF group. The mean duration of symptoms was 21.32 +/- 5.57 months and the mean follow-up was 37.1 months (range, 36 to 38 months), and none of the athletes had prior surgical interventions to the affected knee. Patients were evaluated using modified Hospital for Special Surgery (HSS) and International Cartilage Repair Society (ICRS) scores, radiograph, magnetic resonance imaging (MRI), and clinical assessment. An independent observer performed a follow-up examination after 6, 12, 24, and 36 months. At 12.4 months postoperatively, arthroscopy with biopsy for histologic evaluation was carried out. A radiologist and a pathologist, both of whom were blinded to each patient's treatment, did the radiologic and histologic evaluations.

RESULTS

After 37.1 months, both groups had significant clinical improvement (P < .05). According to the modified HSS and ICRS scores, functional and objective assessment showed that 96% had excellent or good results after OAT compared with 52% for the MF procedure (P < .001). At 12, 24, and 36 months after surgery, the HSS and ICRS showed statistically significantly better results in the OAT group (P = .03; P = .006; P = .006). Younger athletes did better in both groups. No serious complications were reported. There was 1 failure in the OAT group and 9 in the MF group. The ICRS Cartilage Repair Assessment for macroscopic evaluation during arthroscopy at 12.4 months showed excellent or good repairs in 84% after OAT and in 57% after MF. Biopsy specimens were obtained from 58% of the patients and histologic evaluation of repair showed better scores (according to ICRS) for the OAT group (P < .05). MRI evaluation showed excellent or good repairs in 94% after OAT compared with 49% after MF. Twenty-six (93%) OAT patients and 15 (52%) MF patients returned to sports activities at the preinjury level at an average of 6.5 months (range, 4 to 8 months). Others showed a decline in sports activity level.

CONCLUSIONS

At an average of 37.1 months (range, 36 to 38 months) follow-up, our prospective, randomized, clinical study in young active athletes under the age of 40 has shown significant superiority of OAT over MF for the repair of articular cartilage defects in the knee. We found that only 52% of MF athletes could return to sports at the preinjury level. Limitations of our study included a small number of athletes and a relatively short (3-year) follow-up. A long-term follow-up is needed to assess the durability of articular cartilage repair using these methods in young active athletes.

LEVEL OF EVIDENCE

Level I, Therapeutic study, randomized controlled trial, significant difference (a).

Intra-articular hyaluronan following autogenous osteochondral grafting of the knee

PURPOSE

The aim of this study was to assess whether intra-articular hyaluronan viscosupplementation after osteochondral grafting (mosaic arthroplasty) of the knee allowed better graft integration and function in a sheep model.

TYPE OF STUDY

Experimental study.

METHODS

Twelve adult sheep underwent a mosaic arthroplasty procedure to a standardized osteochondral defect on the medial femoral condyle. One week after surgery the animals were randomized to receive a course of weekly intra-articular injections for 5 weeks of either sodium-hyaluronate solution 25 mg/2.5 mL (HA group) or of a 2.5 mL buffer solution (control group). Synovial fluid samples were taken preoperatively, preceding each injection, and at 8 and 12 weeks. The animals were euthanized at 12 weeks, the knees dissected out, and biomechanical and histologic assessments were made.

RESULTS

There was no difference in the synovial fluid leukocyte or total protein concentration between the groups, but the hyaluronan concentration was statistically higher in the HA group. Aggregate moduli of the articular surface were statistically higher in the graft articular cartilage in the HA group than in the control group, as were the sulphated glycosaminoglycan levels. Histologic assessment found more articular cartilage flow in the HA group, whereas there was more interstitial tissue present in the interstices between the grafts in the control group.

CONCLUSIONS

Results from this study suggest that hyaluronan viscosupplementation following osteochondral grafting does convey some beneficial effects on graft cartilage in the early postoperative period in an ovine model.

CLINICAL RELEVANCE

This study suggests that, in the early postoperative period, hyaluronan supplementation improves articular cartilage survival after osteochondral grafting.

Autologous osteochondral transplantation for simple cyst in the patella

Treatment options for chondral and osteochondral defects of the patella have been few and results have been inconsistent at best. Autologous osteochondral transplantation presents a new way to revisit these patellar defects. We report the case of a young female softball player with a simple cyst in the patella and an osteochondral defect that serves as the indication for autograft osteochondral transplantation.

Outcome and risk factors after anterior cruciate ligament reconstruction: a follow-up study of 948 patients

PURPOSE

The aim of the study was to assess the outcome and risk factors after anterior cruciate ligament (ACL) reconstruction in a large group of patients.

TYPE OF STUDY

Case series.

METHODS

Included in this retrospective study were 948 patients (323 female, 625 male) with a symptomatic unilateral ACL rupture, who underwent arthroscopic reconstruction using patellar tendon autograft and interference screw fixation at 3 Swedish hospitals. The median age of the patients at the time of the index operation was 26 years (range, 14 to 53 years). The patients underwent surgery at a median of 12 months (range, 0.5 to 360 months) after their injury. Independent physiotherapists performed the follow-up examinations at a median of 32 months (range, 21 to 117 months) postoperatively.

RESULTS

Of the 948 patients, 550 (58%) underwent meniscal surgery before, during, or after the ACL reconstruction. The median Tegner activity level was 8 (range, 2-10) before injury, 3 (range, 0-9) preoperatively, and 6 (range, 1-10) at follow-up (P < .0001 preoperative v follow-up). At follow-up, the median Lysholm score was 90 points (range, 14-100), the median KT-1000 anterior side-to-side laxity difference was 1.5 mm (range, -6 to 13 mm), and the median 1-leg hop test quotient was 95% (0% to 167%) compared with the contralateral normal side. At follow-up, 69.3% of the patients were classified as normal or nearly normal according to the International Knee Documentation Committee evaluation system. However, 36% of the patients were unable to or had severe problems performing the knee-walking test. Inferior results correlated with increased time period between the index injury and reconstruction and concomitant joint damage found at the index operation.

CONCLUSIONS

Overall, the results were good after ACL reconstruction using patellar tendon autograft and interference screw fixation. Concomitant joint damage and a long time period between the injury and reconstruction are major risk factors for inferior outcome after ACL reconstruction.

LEVEL OF EVIDENCE

Level IV, case series.

Simple solution for failure of trailing sutures when using the EndoButton in anterior cruciate ligament reconstruction: the "Rescue Rein"

In this article, we introduce the technique of adding a second suture in the distal hole of the EndoButton. This suture, the "Rescue Rein," is kept with the graft and is a simple solution for recovering the graft during anterior cruciate ligament reconstruction when the EndoButton becomes jammed within the femoral tunnel and the trailing sutures cannot be removed.

Primary stability of three posterior cruciate ligament reconstruction procedures: a biomechanical in vitro study

PURPOSE

Posterior cruciate ligament (PCL) reconstruction procedures have not been thoroughly evaluated under cyclic loading conditions. We tested the hypothesis that PCL reconstruction with a quadrupled flexor-tendon graft and fixation using tapes and staples is biomechanically superior to that fixed with sutures, a button, and a post-screw, and is comparable to reconstruction with a bone--patellar tendon--bone (BPTB) graft.

STUDY DESIGN

In vitro biomechanical study.

METHODS

A total of 45 porcine knees were used. The quadrupled flexor-tendon graft was fixed using the suture/button/post-screw procedure in 15 knees, and with the tape/staples procedure in another 15 knees. The remaining 15 knees underwent reconstruction with a BPTB graft secured with screws as the standard control. In each group of 15 knees, 5 underwent tensile testing without cyclic loading, and 10 underwent the same tensile test after 5,000 cycles of load-controlled or displacement-controlled loading.

RESULTS

Each type of cyclic loading produced larger biomechanical changes in the knees fixed with the suture/button/post-screw procedure than in the knees secured using the other 2 procedures.

CONCLUSIONS

In PCL reconstruction, the tape/staples procedure is biomechanically superior to the suture/button/post-screw procedure, and is comparable to the BPTB/screws procedure with regard to the ultimate failure load. Neither of the procedures using the quadrupled flexor-tendon graft was comparable to the BPTB graft in linear stiffness and the initial displacement after load-controlled cyclic testing.

CLINICAL RELEVANCE

The biomechanical behaviors of PCL-reconstructed knees are significantly different, depending on surgical techniques.

Fresh osteochondral allografts: results in the patellofemoral joint

Twenty knees in 18 patients were treated (mean age, 42 years; range, 19-64 years) with fresh osteochondral allografting limited to the patellofemoral joint. The knees were analyzed retrospectively to determine the rate of successful outcomes. The trochlea and patella were treated in 12 patients and the patella was treated in eight patients. There were 11 women and seven men. The primary outcome measures were revision allografting, arthrodesis, or arthroplasty, and clinical scoring using a modified Merle D'Aubigné-Postel 18-point scale. Radiographs were available for 12 knees. There were five failures. For the remaining knees, the clinical scores increased from a mean of 11.7 points (range, 7-15 points) to 16.3 points (range, 12-18 points). Of the knees evaluated radiographically, four had no evidence of patellofemoral arthrosis, and six had only mild arthrosis. Fresh osteochondral allografting is a salvage procedure for the young, active patient with severe articular cartilage disease of the patellofemoral joint. The results of this procedure are comparable to results of described other techniques in the literature. If allograft incorporation does occur, the procedure is associated with improved pain, function, range of motion, and a low risk of progressive arthritis.

LEVEL OF EVIDENCE

Level IV (case series--no, or historical control group). See the Guidelines for Authors for a complete description of levels of evidence.

Cyclic loading comparison between biodegradable interference screw fixation and biodegradable double cross-pin fixation of human bone-patellar tendon-bone grafts

PURPOSE

The aim of this study was to compare ultimate load, yield load, stiffness, and displacement after cyclic loading of a cross-pin technique and an interference screw technique for the fixation of bone-patellar tendon-bone (BPTB) grafts in anterior cruciate ligament (ACL) reconstruction.

TYPE OF STUDY

Biomechanical in vitro study.

METHODS

The devices tested were 2 2.7-mm biodegradable pins (RigidFix; Ethicon, Mitek Division, Norderstedt, Germany) and biodegradable interference screws (Absolute; Innovasive Devices, Marlborough, MA). Each device was used for the fixation of 10 8-mm, 9-mm, or 10-mm sized human BPTB grafts in tunnels drilled in bovine knees. Ultimate load, yield load, stiffness, and displacement after cyclic loading (1,000 cycles between 50 and 250 N) were then evaluated.

RESULTS

All 8-mm grafts that were fixed with cross-pins failed after a mean of 124 cycles of load. The 9-mm and 10-mm grafts survived the cyclic loading protocol. Yield load and maximum load of the 10-mm groups (cross-pin and interference screw) were significantly higher than that of the 9-mm groups. There was no significant difference in maximum load, yield load, and stiffness between the cross-pin and interference screw fixation technique for 1 graft size.

CONCLUSIONS

The biomechanical data suggest that femoral fixation of 9-mm and 10-mm BPTB grafts using 2.7-mm biodegradable cross-pins leads to primary stability that is comparable to that of biodegradable interference screws. Fixation of 8-mm BPTB grafts using 2.7-mm biodegradable cross-pins had poor results.

CLINICAL RELEVANCE

The diameter of the bone block is the limiting factor for the final fixation strength and the cyclical survival when using cross-pins. We strongly recommend not using this technique for bone blocks smaller than 9 mm in diameter.

The peashooter device: an invaluable tool for bone grafting during revision anterior cruciate ligament surgery

Anterior cruciate ligament (ACL) reconstruction is a commonly performed surgery. Despite the improved technique and understanding of the rehabilitation rationale, the long-term success rate of good or excellent results is 75% to 90%. That leaves 10% to 25% of reconstructed ACLs with unsatisfactory results. Certainly, revision ACL surgery is not required in every patient. It should be individualized according to symptoms, objective findings, and the expectations of the patients. Revision of a failed ACL reconstruction may be carried out either as a single-stage procedure or a staged procedure. A staged procedure is recommended in cases of tunnel enlargement and/or removal of the implants and the failed graft, which leaves large bone defects. Bone grafting of the tibial bone tunnel defect is usually not a problem. On the other hand, grafting the femoral bone tunnel defect can present a challenge. It is important to place enough bone graft into the femoral tunnel securely and tightly so that bone incorporation takes place before the second-stage surgery, when the new tunnel can be drilled and the new ligament graft placed. We describe a simple technique using the elasticity and transparent properties of a chest drain, which effectively delivers the bone graft to the femoral tunnel defect. We name it the "peashooter device."