Anterior cruciate ligament reconstruction with quadriceps tendon-patellar bone allograft: matched case control study.

BACKGROUND: Quadriceps tendon-patellar bone (QTPB) autograft is an excellent graft option with good clinical outcome. Use of QTPB autografts have increased because they minimize donor-site morbidity including anterior knee pain, while providing adequate mechanical strength. Although, there were many clinical results about allografts that used in anterior cruciate ligament (ACL) reconstruction, it have never been reported about the clinical outcome of ACL reconstruction with QTPB allograft. The purpose of this study is to evaluate the clinical outcome of ACL reconstruction with QTPB allograft and to compare with QTPB autograft. We hypothesized that ACL reconstruction with QTPB allograft had good functional outcomes and stability and no significant difference compared to the ACL reconstruction with QTPB autograft. METHODS: From February 2009 to January 2014, 213 cases who received ACL reconstruction with QTPB grafts were included. Forty-five patients who received ACL reconstruction with QTPB allograft were individually matched in age, sex, direction of the injured knee and body mass index (BMI) to a control group of 45 patients who received QTPB autograft. Clinical results were evaluated using International Knee Documentation Committee (IKDC) score, Lysholm score, Tegner scale, Knee injury and Osteoarthritis Outcome Score (KOOS) and ligament laxity. An average follow-up time was 31.2 months. RESULTS: The functional scores and ligament laxity improved from initial to the last visit in those with ACL reconstruction with QTPB allograft (p < 0.05). No significant statistical difference was found in clinical outcomes and complications including re-rupture between the QTPB allograft and autograft groups (p > 0.05). Laxity using anterior drawer test, Lachman test and KT-2000 showed no significant difference. No significant difference was found between the two groups in quadriceps peak extension torque, except at 60° per second at 6 months. CONCLUSION: QTPB allograft achieved good clinical outcome with no difference compared with QTPB autograft. QTPB allograft for ACL reconstruction is promising alternative to selected and compliant patients. Long-term follow-up needs to further evaluate the clinical outcomes and complications including re-rupture rate.

Long-term follow-up after anterior cruciate ligament reconstruction using a press-fit quadriceps tendon-patellar bone autograft.

BACKGROUND: The use of a quadriceps tendon-patellar bone (QTPB) autograft provides an alternative procedure in primary reconstruction of the anterior cruciate ligament (ACL). Using the press-fit technique for femoral fixation and knotting over a bone bridge as well as additional spongiosa filling for tibial fixation can completely eliminate the need for fixation implants. The objective of this study was to evaluate the long-term clinical, functional and radiological results of this operating method. METHODS: Sixty-nine patients (27 female-42 male) were included in this study. Fifty-seven patients (83%) received a comprehensive follow-up review after an average period of 7.5 years (range: 7-8.7). All other patients were surveyed by telephone. Six patients (9%) suffered a re-rupture of the ACL graft caused by a new related trauma and were therefore excluded from the statistical analysis. RESULTS: Of all patients, 98% were satisfied with the operation. Normal or almost normal results were recorded in the subjective IKDC scores form by 88% of the patients. The Lysholm score demonstrated very good and good results in 83% of the patients. Only 1 patient reported minor complaints in the donor area. Seven (12%) patients developed Cyclops syndrome with limited knee extension. This complication was treated arthroscopically within the first year postoperatively. Their results on follow-up were not worse than the results of the patients without Cyclops syndrome. Regarding the 57 patients who received a comprehensive evaluation, the stability test with the KT-1000 Arthrometer yielded a difference of less than 3 mm in the contralateral comparison for 89% of the operated knees. The pivot-shift test was normal in 79% and almost normal in 21%. In the Single-leg Triple Hop Test, patients achieved an average of 98% of the hopping distance attained with the contralateral leg. The radiological examination revealed a slight deterioration in the Kellgren-Lawrence Score in 2 patients. CONCLUSION: The ACL reconstruction using the QTPB autograft performed with the press-fit technique leads to good results in comparison with published results of established procedures for primary ACL surgery using other autografts. Further investigations should involve comparative studies with the objective of providing evidence-based, individually adapted therapy for ACL rupture.

Risk of Revision Was Not Reduced by a Double-bundle ACL Reconstruction Technique: Results From the Scandinavian Registers.

BACKGROUND: Double-bundle anterior cruciate ligament (ACL) reconstruction has demonstrated improved biomechanical properties and moderately better objective outcomes compared with single-bundle reconstructions. This could make an impact on the rerupture rate and reduce the risk of revisions in patients undergoing double-bundle ACL reconstruction compared with patients reconstructed with a traditional single-bundle technique. The National Knee Ligament Registers in Scandinavia provide information that can be used to evaluate the revision outcome after ACL reconstructions. QUESTIONS/PURPOSES: The purposes of the study were (1) to compare the risk of revision between double-bundle and single-bundle reconstructions, reconstructed with autologous hamstring tendon grafts; (2) to compare the risk of revision between double-bundle hamstring tendon and single-bundle bone-patellar tendon-bone autografts; and (3) to compare the hazard ratios for the same two research questions after Cox regression analysis was performed. METHODS: Data collection of primary ACL reconstructions from the National Knee Ligament Registers in Denmark, Norway, and Sweden from July 1, 2005, to December 31, 2014, was retrospectively analyzed. A total of 60,775 patients were included in the study; 994 patients were reconstructed with double-bundle hamstring tendon grafts, 51,991 with single-bundle hamstring tendon grafts, and 7790 with single-bundle bone-patellar tendon-bone grafts. The double-bundle ACL-reconstructed patients were compared with the two other groups. The risk of revision for each research question was detected by the risk ratio, hazard ratio, and the corresponding 95% confidence intervals. Kaplan-Meier analysis was used to estimate survival at 1, 2, and 5 years for the three different groups. Furthermore, a Cox proportional hazard regression model was applied and the hazard ratios were adjusted for country, age, sex, meniscal or chondral injury, and utilized fixation devices on the femoral and tibial sides. RESULTS: There were no differences in the crude risk of revision between the patients undergoing the double-bundle technique and the two other groups. A total of 3.7% patients were revised in the double-bundle group (37 of 994 patients) versus 3.8% in the single-bundle hamstring tendon group (1952 of 51,991; risk ratio, 1.01; 95% confidence interval (CI), 0.73-1.39; p = 0.96), and 2.8% of the patients were revised in the bone-patellar tendon-bone group (219 of the 7790 bone-patellar tendon-bone patients; risk ratio, 0.76; 95% CI, 0.54-1.06; p = 0.11). Cox regression analysis with adjustment for country, age, sex, menisci or cartilage injury, and utilized fixation device on the femoral and tibial sides, did not reveal any further difference in the risk of revision between the single-bundle hamstring tendon and double-bundle hamstring tendon groups (hazard ratio, 1.18; 95% CI, 0.85-1.62; p = 0.33), but the adjusted hazard ratio showed a lower risk of revision in the single-bundle bone-patellar tendon-bone group compared with the double-bundle group (hazard ratio, 0.62; 95% CI, 0.43-0.90; p = 0.01). Comparisons of the graft revision rates reported separately for each country revealed that double-bundle hamstring tendon reconstructions in Sweden had a lower hazard ratio compared with the single-bundle hamstring tendon reconstructions (hazard ratio, 1.00 versus 1.89; 95% CI, 1.09-3.29; p = 0.02). Survival at 5 years after index surgery was 96.0% for the double-bundle group, 95.4% for the single-bundle hamstring tendon group, and 97.0% for the single-bundle bone-patellar tendon-bone group. CONCLUSIONS: Based on the data from all three national registers, the risk of revision was not influenced by the reconstruction technique in terms of using single- or double-bundle hamstring tendons, although national differences in survival existed. Using bone-patellar tendon-bone grafts lowered the risk of revision compared with double-bundle hamstring tendon grafts. These findings should be considered when deciding what reconstruction technique to use in ACL-deficient knees. Future studies identifying the reasons for graft rerupture in single- and double-bundle reconstructions would be of interest to understand the findings of the present study. LEVEL OF EVIDENCE: Level III, therapeutic study.

Quantitative assessment of patellar vascularity following bone-patellar tendon-bone autograft harvest for ACL reconstruction.

PURPOSE: Recent anatomic studies have suggested that the dominant arterial supply of the patella enters through the inferior pole. Based upon these findings, we hypothesized that bone-patellar tendon-bone graft harvest can significantly diminish patellar vascularity. METHODS: Nine matched pair cadaveric knee specimens (mean age 47.4 years) were dissected and cannulated. A single knee was selected to undergo routine graft harvest, and the contralateral knee was left intact to serve as a control. Gadolinium was injected, and magnetic resonance imaging (MRI) signal enhancement was quantified to determine differences in uptake. Each matched pair was subsequently injected with a urethane polymer compound and dissected to correlate vessel disruption with MRI findings. RESULTS: We identified two predominating patterns of vessel entry. In one pattern, the vessel entered the inferomedial aspect (five o'clock/right, seven o'clock/left) of the patella and was disrupted by graft harvest in 2/9 (22.2 %) pairs. In the second pattern, the vessel entered further medial (four o'clock/right, eight o'clock/left) and was not disrupted (7/9, 78.8 %). The mean decrease in gadolinium uptake following disruption of the predominant vessel measured 56.2 % (range 42.6-69.5 %) compared to an average decrease of 18.3 % (range 7.1-29.1 %) when the dominant arterial supply to the inferior pole remained intact (p < 0.04). CONCLUSION: Medial entry of the predominant vessel precluded vessel disruption. Disruption of the dominant arterial supply can result in a significant decrease in patellar vascularity. Modification of graft harvest techniques and areas of surgical dissection should be explored to minimize vascular insult. Further correlation with clinical studies/outcomes is necessary to determine a potential association between vascular insult and anterior knee pain.

Double-layer versus single-layer bone-patellar tendon-bone anterior cruciate ligament reconstruction: a prospective randomized study with 3-year follow-up.

PURPOSE: To evaluate the clinical results of a randomized controlled trial of single-layer versus double-layer bone-patellar tendon-bone (BPTB) anterior cruciate ligament (ACL) reconstruction. METHODS: Fifty-eight subjects who underwent primary ACL reconstruction with a BPTB allograft were prospectively randomized into two groups: single-layer reconstruction (n = 31) and double-layer reconstruction (n = 27). The following evaluation methods were used: clinical examination, KT-1000 arthrometer measurement, muscle strength, Tegner activity score, Lysholm score, subjective rating scale regarding patient satisfaction and sports performance level, graft retear, contralateral ACL tear, and additional meniscus surgery. RESULTS: Forty-eight subjects (24 in single-layer group and 24 in double-layer group) who were followed up for 3 years were evaluated. Preoperatively, there were no differences between the groups. At 3-year follow-up, the Lachman and pivot-shift test results were better in the double-layer group (P = 0.019 and P < 0.0001, respectively). KT measurements were better in the double-layer group (mean 2.9 versus 1.5 mm; P = 0.0025). The Tegner score was also better in the double-layer group (P = 0.024). There were no significant differences in range of motion, muscle strength, Lysholm score, subjective rating scale, graft retear, and secondary meniscal tear. CONCLUSIONS: In ACL reconstruction, double-layer BPTB reconstruction was significantly better than single-layer reconstruction regarding anterior and rotational stability at 3-year follow-up. The results of KT measurements and the Lachman and pivot-shift tests were significantly better in the double-layer group, whereas there was no difference in the anterior drawer test results. The Tegner score was also better in the double-layer group; however, there were no differences in the other subjective findings.

Incidence and risk factors of allograft bone failure after calcaneal lengthening.

BACKGROUND: Calcaneal lengthening with allograft is frequently used for the treatment of patients with symptomatic planovalgus deformity; however, the behavior of allograft bone after calcaneal lengthening and the risk factors for graft failure are not well documented. QUESTIONS/PURPOSES: (1) What proportion of the patients treated with allograft bone had radiographic evidence of graft failure and what further procedures were performed? (2) What are the risk factors for radiographic graft failure after calcaneal lengthening? (3) What patient factors are associated with the magnitude of correction achieved after calcaneal lengthening? METHODS: Between May 2003 and January 2014, we performed 341 calcaneal lengthenings on 202 patients for planovalgus deformity, the etiology of which included idiopathic, cerebral palsy, and other neuromuscular disease. Of these, 176 patients (87%) had adequate followup for graft evaluation, defined as lateral radiographs taken before and at least 6 months after the index procedure (mean, 18 months; range, 6-100 months) and 117 patients (58%) had adequate followup for the assessment of the extent of correction, defined as weightbearing anteroposterior and lateral radiographs taken before and at least 1 year after the index procedure (mean, 24 months; range, 12-96 months). These patients' results were evaluated retrospectively. The Goldberg scoring system was chosen for demonstration of allograft behavior. A score lower than 6 at 6 months after surgery was defined as radiographic graft failure; the highest possible score was 7 points, and this represented graft incorporation with excellent reorganization of the graft and no loss of height. The patient age, sex, diagnosis, graft material, ambulatory status, and use of antiseizure medication were evaluated as possible risk factors, and we controlled for the interaction of potentially confounding variables using multivariate analysis. Additionally, six radiographic indices were analyzed for their effects on the extent of correction. RESULTS: The mean estimated Goldberg score was 6 (SD, 1.14) at 6 months after calcaneal lengthening with 11 feet (4%) classified as radiographic graft failure (Goldberg score < 6). Of these, four feet (1%) underwent reoperation using an iliac autograft bone resulting from pain and loss of correction. Multivariate analysis showed that the tricortical iliac crest allograft was superior to the patellar allograft (odds ratio [OR], 3.2; 95% confidence interval [CI], 1.1-9.8; p = 0.038) and the possibility of radiographic graft failure was found to increase along with age (OR, 1.2; 95% CI, 1.0-1.3; p = 0.006). Radiographically, the extent of correction was found to decrease with patient age, as observed at the anteroposterior talus-first metatarsal angle (p < 0.001), lateral talocalcaneal angle (p < 0.001), lateral talus-first metatarsal angle (p < 0.001), and relative calcaneal length (p = 0.041). CONCLUSIONS: Graft failure can occur after calcaneal lengthening using allograft. Our study showed that the tricortical iliac allograft was superior to the patellar allograft, and further studies are warranted to further elucidate the effects of age on radiographic graft failure. LEVEL OF EVIDENCE: Level III, therapeutic study.

Biomechanical evaluation of anatomic single- and double-bundle anterior cruciate ligament reconstruction techniques using the quadriceps tendon.

PURPOSE: Quadriceps tendon grafts have renewed interest for ACL reconstruction; however, biomechanical studies comparing anatomic single-bundle (SB) and double-bundle (DB) reconstruction techniques are rare. The purpose of this study was to compare the knee biomechanics in four different types of anatomic ACL reconstruction techniques, using the quadriceps tendon in a human cadaver. METHODS: Four different tibial (T) and femoral (F) tunnel configurations, (a) DB-2F-2T, (b) DB-2F-1T, (c) SB-1F-1T and (d) DB-1F-2T, were used for ACL reconstruction using the split quadriceps tendon with patella bone. Ten cadaver knees were subjected to an 89 N anterior tibial load and combined 7 N m valgus and 5 N m internal torques. The anterior tibial translation (ATT) and in situ force were measured using a robotic system for the ACL-intact, ACL-deficient and ACL-reconstructed knees. RESULTS: DB reconstructions mostly restored ATT to the intact ACL. The in situ forces under the anterior load in the DB reconstructions were similar to the intact ACL, but that of the SB reconstruction was different at 30°, 60° and 90° of flexion (P < 0.05). Under combined torques, the in situ force of the SB graft was less than that of intact ACL at 0°, 15° and 30° of knee flexion (P < 0.05), while that of the ACL DB reconstruction was similar to the intact ACL. CONCLUSION: DB ACL reconstruction using quadriceps tendon can restore biomechanics of the knee to that of the intact ACL regardless of whether three or four tunnels are used, but SB reconstruction does not.

Experimental remodellation of extracorporeal irradiated autogenous and allogenic patellar grafts.

BACKGROUND: Irradiated autografts have been used to aid the recovery of bone defects, and the results are well documented. Recently, bone allografts with tendinous attachments have been used to restore the function of joints. Similar reconstructions can be performed with irradiated autografts. However, little information is available on the biology of extracorporeal irradiated tendon autografts. QUESTIONS/PURPOSES: An experimental rabbit model was used to investigate the quality of healing and remodeling of the irradiated autogenous patellar tendon graft after 3 and 12 weeks using immunohistochemical and morphometric analyses. METHODS: New Zealand rabbits (n = 40) were randomly divided into autograft and allograft groups. The right knees of all animals served as the control (sham). The patellar tendon graft of the control right knee was reimplanted into its original location without any processing, while the patellar tendon of the left knee in the autograft group was reimplanted into the original location after 50 Gy irradiation. In the allograft group, the patellar tendon was sutured to the knee of another rabbit following 50 Gy irradiation. Five rabbits from each group were sacrificed and examined histologically. RESULTS: There were significant differences in the number of fibroblasts after 12 weeks between allograft and sham groups (P = 0.002). On the other hand, there were no differences between the allograft and autograft groups at the 12th week (P = 0.139). The difference in fibroblast numbers between autograft and allograft groups was statistically significant after the 3rd week (P < 0.05). Collagen fibril thickness was different between both the allograft and sham groups (P = 0.002) and the allograft and autograft groups at the 12th week (P = 0.000). Collagen fibrils were thicker in the sham and autograft groups compared with the allograft group at the 3rd week of evaluation (P < 0.05). The Ki67 index was significantly different between the allograft and sham groups at the 12th week (P < 0.032), while there was no difference between the allograft and autograft groups (P > 0.05). At the 3rd week, Ki67 reactivity was higher in the allograft group compared with the other two groups (P < 0.05).

Advanced patellofemoral cartilage lesions in patients younger than 50 years of age: is there an ideal operative option?

PURPOSE: The purpose of this review was to determine if there is an ideal operation for large symptomatic articular cartilage lesions on the undersurface of the patella in young patients. METHODS: A systematic search of PubMed was conducted to determine the outcome of operations performed for large patellar lesions in young patients. Inclusionary criteria were English language, original clinical trials published from 1992 to 2012, patellar lesions 4 cm(2) or larger, mean patient age 50 years or younger, and all evidence levels. RESULTS: Of 991 articles identified, 18 met the inclusionary criteria, encompassing 840 knees in 828 patients. These included 613 knees that underwent autologous chondrocyte implantation (ACI) (11 studies), 193 knees that had patellofemoral arthroplasty (PFA) (5 studies), and 34 knees that underwent osteochondral allografting (OA) (2 studies). The mean patient age was 37.2 years and the mean follow-up was 6.2 years. Long-term follow-up (>10 years) was available in only 4 studies (2 PFA, 1 ACI, 1 OA). All studies except one were Level IV and none were randomized or had a control group. Twenty-one outcome instruments were used to determine knee function. When taking into account knees that either failed or had fair/poor function, the percentage of patients who failed to achieve a benefit averaged 22% after PFA and 53% after OA and ranged from 8% to 60% after ACI. In addition, all 3 procedures had unacceptable complication and reoperation rates. CONCLUSIONS: The combination of failure rates and fair/poor results indicated that all 3 procedures had unpredictable results. We concluded that a long-term beneficial effect might not occur in one of 3 ACI and PFA procedures and in 2 of 3 OA procedures. We were unable to determine an ideal surgical procedure to treat large symptomatic patellar lesions in patients 50 years or younger. LEVEL OF EVIDENCE: Level IV, systematic review of Level I to IV studies.

Fracture of the proximal tibia after revision total knee arthroplasty with an extensor mechanism allograft.

Extensor mechanism reconstruction with an extensor mechanism allograft (EMA) remains one of the most reliable methods for treating the extensor mechanism deficient total knee arthroplasty. We report 3 patients who were treated with an EMA who sustained a proximal tibial shaft fracture. In all 3 cases, a short tibial component was present that ended close to the level of the distal extent of the bone block. When performing an EMA, it is important to recognize that the tibial bone block creates a stress riser and revision to a long-stemmed tibial component should be strongly considered to bypass this point to minimize the risk of fracture.

Anterior cruciate ligament (ACL) reconstruction with quadriceps tendon autograft and press-fit fixation using an anteromedial portal technique.

BACKGROUND: This article describes an arthroscopic anterior cruciate ligament (ACL) reconstruction technique with a quadriceps tendon autograft using an anteromedial portal technique. METHODS: A 5 cm quadriceps tendon graft is harvested with an adjacent 2 cm bone block. The femoral tunnel is created through a low anteromedial portal in its anatomical position. The tibial tunnel is created with a hollow burr, thus acquiring a free cylindrical bone block. The graft is then passed through the tibial tunnel and the bone block, customized at its tip, is tapped into the femoral tunnel through the anteromedial portal to provide press-fit fixation. The graft is tensioned distally and sutures are tied over a bone bridge at the distal end of the tibial tunnel. From the cylindrical bone block harvested from the tibia the proximal end is customized and gently tapped next to the graft tissue into the tibial tunnel to assure press fitting of the graft in the tibial tunnel. The distal part of the tibial tunnel is filled up with the remaining bone.All patients were observed in a prospective fashion with subjective and objective evaluation after 6 weeks, 6 and 12 months. RESULTS: Thirty patients have been evaluated at a 12 months follow-up. The technique achieved in 96.7% normal or nearly normal results for the objective IKDC. The mean subjective IKDC score was 86.1 ± 15.8. In 96.7% the Tegner score was the same as before injury or decreased one category. A negative or 1+ Lachman test was achieved in all cases. Pivot-shift test was negative or (+) glide in 86.7%. The mean side-to-side difference elevated by instrumental laxity measurement was 1.6 ± 1.1 mm. Full ROM has been achieved in 92.3%. The mean single one-leg-hop index was 91.9 ± 8.0 at the follow-up. CONCLUSIONS: Potential advantages include minimum bone loss specifically on the femoral side and graft fixation without implants.

Patellar dislocation in skeletally immature patients: semitendinosous and gracilis augmentation for combined medial patellofemoral and medial patellotibial ligament reconstruction.

PURPOSE: Patellar instability is a frequent condition in children and adolescents. The problem can be associated with malalignment resulting from different anatomical abnormalities. Several surgical procedures have been suggested for recurrent patellar dislocation consequent to failed conservative treatment. METHODS: We present an original surgical procedure for reconstructing both the medial patellofemoral (MPFL) and medial patellotibial ligaments (MPTL) by semitendinosus (ST) tendon with gracilis (G) autograft augmentation in skeletally immature patients with recurrent patellar dislocation. RESULTS: This technique is effective and permits satisfactory patellar congruency documented by static and dynamic CT. CONCLUSIONS: The operation is associated with optimal functional results and is minimally invasive, causing no growth disturbance. LEVEL OF EVIDENCE: Expert opinion, Level V.

Repair of insertional achilles tendinosis with a bone-quadriceps tendon graft.

BACKGROUND: While conservative treatment may be successful in most cases, partial rupture at the calcaneal insertion point is a significant concern with insertional Achilles tendinopathy. We report on the outcomes of a surgical technique for Achilles tendon augmentation using a bone-tendon graft harvested from the knee extensor system. MATERIALS AND METHODS: Our retrospective case series includes 25 surgical procedures performed in 24 patients, 19 males and five females, with a mean age of 47 (range, 30 to 59) years, 18 of whom were athletes. The mean followup period was 52 (range, 12 to 156) months. All patients underwent MRI examination prior to surgery which showed partial Achilles tendon rupture. The Achilles tendon was debrided through a posterolateral approach. The bone-quadriceps tendon graft was harvested, then the bone plug of the graft was inserted into a blind tunnel drilled into the calcaneus and fixed with an interference screw. The fibers of the quadriceps tendon were sutured to the residual part of the Achilles tendon with the foot at an angle of 90 degrees. RESULTS: Patients were able to resume their sporting activity after an average of 6.7 months. At last followup examination, physical activity was scored 5.2 on the 10-point Tegner Scale; the mean AOFAS score was 98.4. MRI examination showed good graft integration 1 year postoperatively. CONCLUSION: The bone-quadriceps tendon grafting technique was a good alternative for the insertional Achilles lesions with partial detachment which we felt required augmentation.

Mapping subchondral bone density of selected donor and recipient sites for autologous osteochondral transplantation in the canine stifle joint using computed tomographic osteoabsorptiometry.

OBJECTIVE: To characterize donor and recipient sites for autologous osteochondral transplantation (AOT) in the canine stifle joint with respect to maximal subchondral bone density (mSBD). STUDY DESIGN: Descriptive laboratory study. SAMPLE POPULATION: Femora (n=15) of dogs (>20 kg). METHODS: mSBD at selected donor sites within and outside the femoropatellar joint and at potential recipient sites for both femoral condyles was assessed using nonvolumetric computed tomographic osteoabsorptiometry and normalized to values obtained at the central weight-bearing aspect of the lateral femoral condyle. RESULTS: Only transplants harvested at the axial aspects of the lateral and medial trochlear ridge had a normalized mSBD comparable with the lateral and medial femoral condyle. Grafts from outside the femoropatellar joint, at the most proximal aspect of the medial femoral condyle and at the most distal aspect of the trochlea (the notch area) had mSBD values 13.8-24.4% less than at the femoral condyles. CONCLUSIONS: Choosing between donor sites within or outside the femoropatellar joint may significantly affect subchondral bone quality of harvested transplants. CLINICAL RELEVANCE: Donor sites abaxial to the femoropatellar joint and at the most proximal aspect of the medial femoral condyle may provide transplants of suboptimal bone morphology, challenging their use as primary donor sites for AOT in dogs. However, this statement is based on nonvolumetric assessment of bone density, necessitating verification using volumetric density analysis to finally infer the biomechanical value of different grafts.

Evaluation of posterolateral rotatory knee instability using the dial test according to tibial positioning.

PURPOSE: This study examined the effect of the anteroposterior (AP) direction force on the tibial external rotation of a posterior cruciate ligament (PCL)/posterolateral corner (PLC)-deficient knee in a clinical setting. METHODS: Between December 2006 and December 2007, 21 patients with a PCL-PLC injury were assessed using a dial test. The thigh-foot angle (TFA) and patella-tubercle angle (PTA) were measured with an external rotation stress applied to the tibia at both 30 degrees and 90 degrees of knee flexion in 2 different positions (reduced and posterior subluxed). The test was performed with the patient in the supine position and with an AP force applied to the tibia by an assistant. To reduce intra- and interobserver bias, the measurements were taken twice by 2 orthopaedic surgeons for all patients. RESULTS: In the subluxed position, the mean side-to-side differences in the TFA at 30 degrees and 90 degrees knee flexion were 12.6 degrees +/- 2.0 degrees and 12.3 degrees +/- 1.4 degrees , respectively. In the reduced position, the mean side-to-side differences in the TFA at 30 degrees and 90 degrees knee flexion were 18.4 degrees +/- 1.4 degrees and 18.5 degrees +/- 1.5 degrees , respectively. In the subluxed position, the mean side-to-side differences in the PTA at 30 degrees and 90 degrees knee flexion were 9.1 degrees +/- 0.8 degrees and 9.0 degrees +/- 0.7 degrees , respectively. In the reduced position, the mean side-to-side differences in the PTA at 30 degrees and 90 degrees knee flexion were 13.3 degrees +/- 0.6 degrees and 13.2 degrees +/- 0.6 degrees , respectively. CONCLUSIONS: The reduction of a posteriorly subluxed knee increased the tibial external rotation (TFA and PTA) during the dial test of combined PCL-PLC injuries in a clinical setting. The accuracy of the dial test may help present surgeons from missing a combined PLC injury that should be corrected in a PCL deficient knee. LEVEL OF EVIDENCE: Level I, testing of previously developed diagnostic criteria in series of consecutive patients.

Use of patella allograft for anterior cervical diskectomy and fusion.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: The purpose of this study is to determine the fusion rates of a consecutive series of anterior cervical decompressions and fusions with allograft patella using both static and dynamic plates. SUMMARY OF BACKGROUND DATA: Anterior cervical diskectomy and fusion (ACDF) has been shown to improve symptoms of radiculopathy and myelopathy. The gold standard for obtaining fusion is using autogenous iliac crest bone graft (ICBG). The complication rate of using ICBG can be as high as 20%. To minimize this morbidity, various forms of allograft are presently used. We have used patellar allograft that we hypothesize exhibits a good combination of strength and sufficient porosity to facilitate fusion. METHODS: A consecutive series of 179 levels in 136 patients who underwent single and multilevel ACDF with allograft patella were retrospectively investigated. Final follow-up lateral cervical spine radiographs were evaluated for evidence of bony fusion. Fusions were graded independently by 2 of the investigators according to an interbody fusion classification proposed by Bridwell and colleagues, Spine, 1995. Fusion rates were compared with historical controls for single-level ACDF with autogenous ICBG and plating. Multivariate analysis was used to evaluate plate type, smoking, revision rate, and Odom's criteria compared with fusion. RESULTS: Ninety-one consecutive single and 81 multilevel anterior cervical decompression and fusions with allograft patella were reviewed. Demographics were similar (average age 47.75 y). Average follow-up was 19.3 months. Fusion rates were 86% (159/179). Our revision rate was 8%. Eighty-one percent (85/98) union rate was noted in the single-level group, and 85% (69/81 levels) or 74% (28/38 patients) in the multilevel group. CONCLUSIONS: Fusion rates were 86%. Plate design (static vs. dynamic) did not seem to affect fusion rates or clinical outcomes. There was a higher nonunion rate at the most inferior level of the multilevel fusions. Nonunions in the dynamic group were more commonly revised and had more kyphosis at final follow-up.

Extensor Mechanism Allograft in Osteosarcoma of the Patella: A Case Report.

CASE: A 24-year-old female diagnosed with fibroblastic osteosarcoma of the patella underwent a total patellectomy and surgical reconstruction with a large bone-tendon allograft of the extensor mechanism and adjuvant chemotherapy. At 5 years' postoperative, the patient has adequate disease control and excellent joint function. CONCLUSIONS: Reconstruction with an extensor mechanism allograft is an appropriate alternative for patients with malignant patella tumors without tumor contamination of the joint, allowing for satisfactory knee function and disease control.

Long-Term Results of Patellar Bone-Grafting for Severe Patellar Bone Loss During Revision Total Knee Arthroplasty.

BACKGROUND: There is no consensus on managing severe patellar bone loss after total knee arthroplasty. We previously described an initial series involving a novel technique of patellar bone-grafting with a short follow-up. The purpose of this study was to determine long-term survivorship and the radiographic and clinical results of patellar bone-grafting during revision total knee arthroplasty in a larger series with an extended follow-up. METHODS: We identified 90 patients from a single institution who underwent 93 patellar bone-grafting procedures for severe patellar bone loss from 1997 to 2014. The mean age of the patients was 70 years, and 46% of patients were female. Forty-five knees (48%) underwent first-time revisions, and 19 knees (20%) had undergone a failed attempt at patellar resurfacings. Intraoperative patellar caliper thickness increased from a mean of 7 to 25 mm after patellar bone-grafting (p < 0.01). Radiographic review determined changes in patellar height, tracking, and remodeling. Knee Society scores (KSSs) were calculated. The mean follow-up was 8 years (range, 2 to 18 years). Kaplan-Meier methods determined survivorship free of any revision and any reoperation. Cox proportional hazards analysis determined predictive factors for failure. RESULTS: Survivorship free of patellar revision was 96% at 10 years. Survivorship free of any revision was 84% at 10 years. Survivorship free of any reoperation was 78% at 10 years. Increasing patient age was the only protective factor against further patellar revision (hazard ratio, 0.95; p < 0.01). When comparing initial radiographs with final radiographs, patellar height decreased from 22 to 19 mm (p < 0.01), 80% compared with 59% of patellae articulated centrally in the trochlea (p = 0.01), and 32% compared with 77% had remodeling over the lateral femoral condyle (p < 0.01). Anterior knee pain decreased from 51% to 27% postoperatively (p = 0.01). The mean knee flexion improved from 101° to 108° (p = 0.03). The mean KSS improved from 50 to 85 points (p < 0.01). CONCLUSIONS: Reliable long-term clinical results can be expected with patellar bone-grafting for severe patellar bone loss during revision total knee arthroplasty. Pain, range of motion, and other reported outcomes improve despite radiographic changes to patellar height, tracking, and remodeling. This technique is a durable and reliable option when standard patellar resurfacing is not possible. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Rectangular tunnel double-bundle anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft to mimic natural fiber arrangement.

We describe our current technique of anatomic, double-bundle (DB), rectangular tunnel anterior cruciate ligament (ACL) reconstruction with bone-patellar tendon-bone (BPTB) graft. This technique mimics the natural, or anatomic, arrangement of the native ACL fibers. This technique has the following advantages: (1) creation of a DB ACL reconstruction with a single BPTB graft; (2) maximization of graft-tunnel contact area; (3) containment of the tunnel apertures within the anatomic ACL attachment footprint; (4) rotational control of the graft within the tunnels during and after fixation; and (5) preservation of notch anatomy.