Arne Kristian Aune

Four-Strand Hamstring Tendon Autograft Compared with Patellar Tendon-Bone Autograft for Anterior Cruciate Ligament Reconstruction A Randomized Study with Two-Year Follow-Up

Seventy-two patients with subacute or chronic rupture of the anterior cruciate ligament were randomly assigned to autograft reconstruction with four-strand gracilis and semitendinosus tendon (N = 37) or with patellar tendon-bone (N = 35) from the ipsilateral side. The groups were similar in terms of age, sex, level of activity, degree of laxity, meniscal lesions found surgically, and rehabilitation program. The follow-up was performed at another hospital by independent observers after 6, 12, and 24 months. Sixty-one patients (32 with hamstring tendon grafts and 29 with patellar tendon grafts) complied with the follow-up routine for the full 24 months. No differences were found between the groups with respect to Cincinnati functional score, KT-1000 arthrometer measurements, or stairs hopple test results. The subjective result and the single-legged hop test result were better for the hamstring tendon group after 6 and 12 months, but no differences were found after 24 months. The hamstring tendon group showed better isokinetic knee extension strength than did the patellar tendon group after 6 months, but not after 12 and 24 months. There was a significant weakness in isokinetic knee flexion strength among the hamstring tendon group. Anterior knee pain was not significantly different between the groups, but kneeling pain was significantly less common in the hamstring tendon group after 24 months.

Knee Function and Prevalence of Knee Osteoarthritis After Anterior Cruciate Ligament Reconstruction A Prospective Study With 10 to 15 Years of Follow-up

Background Few prospective long-term studies of more than 10 years have reported changes in knee function and radiologic outcomes after anterior cruciate ligament (ACL) reconstruction. Purpose To examine changes in knee function from 6 months to 10 to 15 years after ACL reconstruction and to compare knee function outcomes over time for subjects with isolated ACL injury with those with combined ACL and meniscal injury and/or chondral lesion. Furthermore, the aim was to compare the prevalence of radiographic and symptomatic radiographic knee osteoarthritis between subjects with isolated ACL injuries and those with combined ACL and meniscal and/or chondral lesions 10 to 15 years after ACL reconstruction. Study Design Cohort study; Level of evidence, 2. Methods Follow-up evaluations were performed on 221 subjects at 6 months, 1 year, 2 years, and 10 to 15 years after ACL reconstruction with bone-patellar tendon-bone autograft. Outcome measurements were KT-1000 arthrometer, Lachman and pivot shift tests, Cincinnati knee score, isokinetic muscle strength tests, hop tests, visual analog scale for pain, Tegner activity scale, and the Kellgren and Lawrence classification. Results One hundred eighty-one subjects (82%) were evaluated at the 10- to 15-year follow-up. A significant improvement over time was revealed for all prospective outcomes of knee function. No significant differences in knee function over time were detected between the isolated and combined injury groups. Subjects with combined injury had significantly higher prevalence of radiographic knee osteoarthritis compared with those with isolated injury (80% and 62%, P = .008), but no significant group differences were shown for symptomatic radiographic knee osteoarthritis (46% and 32%, P = .053). Conclusion An overall improvement in knee function outcomes was detected from 6 months to 10 to 15 years after ACL reconstruction for both those with isolated and combined ACL injury, but significantly higher prevalence of radiographic knee osteoarthritis was found for those with combined injuries.

Dynamic hip screw with trochanteric stabilizing plate in the treatment of unstable proximal femoral fractures: a comparative study with the Gamma nail and compression hip screw.

OBJECTIVE To compare the results after operative treatment of unstable per- and subtrochanteric fractures with the Gamma nail, compression hip screw (CHS), or dynamic hip screw with a laterally mounted trochanteric stabilizing plate (DHS/TSP). DESIGN Prospective. PATIENTS One hundred seventy patients with unstable trochanteric femoral fractures surviving six months after operation. Eighty-five patients were randomized to treatment with the Gamma nail (n = 50, Gamma group) or the compression hip screw (n = 35, CHS group) and compared with a consecutive series of eighty-five patients operated with the dynamic hip screw with a laterally mounted trochanteric stabilizing plate (DHS/TSP group) MAIN OUTCOME MEASUREMENTS Radiographs were analyzed for fracture classification, evaluation of fracture reduction, implant positioning, later fracture dislocation, and other complications. Pre- and postoperative functional status of the patients were recorded, with a minimum of six months follow-up. RESULTS Eighteen percent of the patients in the Gamma group, 34 percent in the CHS group, and 9 percent in the DHS/TSP group suffered significant secondary fracture dislocation during the six months follow-up, leading to a varus malunion, lag screw cutout, or excessive lag screw sliding with medialization of the distal fracture fragment. Two patients (4.0 percent) in the Gamma group suffered an implant-related femoral fracture below the nail, and one had a deep infection. The reoperation rates were 8.0 percent in the Gamma group, 2.9 percent in the CHS group, and 5.9 percent in the DHS/TSP group. All but one fracture in the Gamma and CHS groups and two fractures in the DHS/TSP group healed within six months. Approximately three-fourths of the patients had returned to their preoperative walking ability after six months, with a trend toward better functional outcome in the DHS/TSP group. Use of a TSP reduced the secondary lag screw sliding as compared with the conventional CHS, without affecting fracture healing. CONCLUSION The TSP may be an aid in the treatment of these difficult fractures because the problem with femoral shaft fractures using the Gamma nail is avoided and the medialization of the distal fracture fragment frequently associated with the CHS is prevented.

Comparison of Failure Strength Between Metallic and Absorbable Interference Screws Influence of Insertion Torque, Tunnel-Bone Block Gap, Bone Mineral Density, and Interference

Because of the good initial fixation strength of interfer ence screws used in anterior cruciate ligament recon struction, metal interference screws have become the standard method for fixation of bone-patellar tendon- bone grafts. To avoid some of the complications with metal screws, a bioabsorbable interference screw was developed. Data on fixation strength in older human cadavers indicate a similar failure strength between bioabsorbable and metal screws. We studied the fail ure mechanisms, insertion torques, and fixation strengths of absorbable and metal interference screws in cadaveric knees from young and middle-aged do nors. With identical gap and screw size, the mean insertion torque for the metal screws (mean, 1.5 N-m; SD, 0.8) was significantly higher than for the absorb able screws (mean, 0.3 N-m; SD, 0.19). The mean failure load for the metal screws (mean 640 N; SD, 201) was also significantly higher than for the absorb able screws (mean, 418 N; SD, 118).

No Difference in Knee Function or Prevalence of Osteoarthritis After Reconstruction of the Anterior Cruciate Ligament With 4-Strand Hamstring Autograft Versus Patellar Tendon–Bone Autograft A Randomized Study With 10-Year Follow-up

Background The choice of different graft types and surgical techniques used when reconstructing a torn anterior cruciate ligament may influence the long-term prevalence of osteoarthritis and functional outcomes. Hypothesis There are no differences in the prevalence of knee osteoarthritis or knee function in patients undergoing reconstruction of a torn anterior cruciate ligament with 4-strand hamstring autograft versus patellar tendon—bone autograft. Study Design Randomized controlled trial; Level of evidence, 1. Methods Seventy-two patients with subacute or chronic rupture of the anterior cruciate ligament were randomly assigned to autograft reconstruction with 4-strand gracilis and semitendinosus tendon (HAM) (N = 37) or with patellar tendon—bone (PTB) (N = 35) from the ipsilateral side. Outcome measurements were the Cincinnati knee score, single-legged hop tests, isokinetic muscle strength tests, pain, knee joint laxity test (KT-1000 arthrometer), and a radiologic evaluation (Kellgren and Lawrence) at 10-year follow-up. Results At 10 years, 57 patients (79%) were eligible for evaluation—29 in the HAM group and 28 in the PTB group. No differences were found between the 2 graft groups with respect to the Cincinnati knee score, the single-legged hop tests, pain, muscle strength measurements, or knee joint laxity. Fifty-five percent and 64% of the patients had osteoarthritis corresponding to Kellgren and Lawrence grade 2 or more in the HAM and the PTB groups, respectively (P = .27). For the uninvolved knee, the corresponding numbers were 28% and 22% (P = .62). Conclusion At 10 years postoperatively, no statistically significant differences in clinical outcome between the 2 graft types were found. The prevalence of osteoarthritis was significantly higher in the operated leg than in the contralateral leg, but there were no significant differences between the 2 groups. The results indicate that the choice of graft type after an anterior cruciate ligament injury has minimal influence on the prevalence of osteoarthritis 10 years after surgery.

Gamma nail vs compression screw for trochanteric femoral fractures: 15 reoperations in a prospective, randomized study of 378 patients

A total of 378 trochanteric and subtrochanteric femoral fractures were randomized to treatment with Gamma nail (177) or Hip Compression Screw (HCS) (201). After a median follow-up time of 17 (10-27) months, 15 patients needed reoperations; 13 had been treated with Gamma nail and 2 with HCS. 10 patients, all treated with Gamma nail, were reoperated because of a femoral shaft fracture. 5 of these fractures occurred 8 (4-10) days postoperatively and were related to intraoperative complications. The other 5 shaft fractures occurred a median of 2 (1-3) months postoperatively after falls, and may be related to stress concentration at the tip of the solid nail. The lag screw cut out or penetrated the femoral head in 5 patients, 3 of them treated with Gamma nail and 2 with HCS.

Interference screw fixation of hamstring vs patellar tendon grafts for anterior cruciate ligament reconstruction.

Abstract The present study was designed to investigate the fixation strength of a quadruple semitendinosus-gracilis graft compared with a middle-third bone-patellar tendon-bone graft using a new interference screw developed to fix hamstrings grafts for ACL reconstructions (RCI, Smith & Nephew Donjoy). Five pairs of human cadaveric knees from donors with a mean age of 43 (range 33–52) years were used. One knee of each pair was randomly allocated to be reconstructed on the femoral side with a semitendinosus-gracilis graft from the same donor using RCI screw fixation. As the control, the contralateral knee was correspondingly reconstructed with a bone-patellar tendon-bone graft using the same interference screw. The grafts were pulled out at a velocity of 30 mm/s by an axially applied load using a MTS machine. The mean (SD) failure load for the bone-patellar tendon-bone graft fixations was 505 (25) N, 110% stronger than the mean failure load for the semitendinosus-gracilis graft fixations, which was 240 (47) N (P = 0.003). The stiffness for the patellar tendon-bone graft fixations was 46 (11) N/mm, 120% stiffer than the semitendinosus-gracilis graft fixations, which was 22 (11) N/mm (P = 0.01). This study shows that the interference screw principle used for ACL reconstructions with hamstrings tendons is inferior to that for bone-patellar tendon-bone reconstructions although the screw was developed especially for soft-tissue fixation in bone tunnels.

Fracture healing and callus innervation after peripheral nerve resection in rats.

The effects of femoral and sciatic nerve resection on fracture healing and innervation of the fracture callus were studied using a stable fracture model. In 34 rats the right tibia was subjected to a standardized closed fracture and stabilized with a modular intramedullary nail. In half of the animals, resection of 1 cm of the femoral and sciatic nerves was performed (nerve resection group), whereas the other animals had sham operations (sham group). To avoid unequal loadbearing between the two groups, all fractured hindlimbs were immobilized in a plaster of Paris cast. The trial was terminated after 5 weeks of fracture healing. Callus size was scored radiographically, and bone mineralization was measured by 85Strontium incorporation. Seven rats from each group had immunohistochemical examination for neural regeneration and ingrowth. Antisera for protein gene product 9.5, necurofilaments, neural growth associated protein 43/B-50, calcitonin gene related peptide, and substance P were used. The mechanical properties of the healing fractures were recorded in a three-point cantilever bending test After 5 weeks, the normally innervated, fractured tibias had regained approximately 50% strength compared with the unfractured side, in comparison with only 20% in the animals that had nerve resection. Although the fracture calluses were mechanically weaker, they were significantly larger in the nerve resection group, indicating defects in tissue composition or organization rendered by the nerve injury. The mineralization rate, as measured by 85Strontium incorporation, was the same in the two groups. However, the nerve resection did not provide complete denervation but changed the innervation pattern of the healing fracture, as the density of sensory nerve fibers immunostainlng for substance P and neu-rofilaments was less in the group with femoral and sciatic nerve resection. The results suggest that intact innervation is essential for normal fracture healing because nerve injury induced a large, but mechanically insufficient, fracture callus.

Changes in Knee Osteoarthritis, Symptoms, and Function After Anterior Cruciate Ligament Reconstruction A 20-Year Prospective Follow-up Study

Background: Progression of tibiofemoral (TF) and patellofemoral (PF) osteoarthritis (OA) and changes in knee function more than 15 years after anterior cruciate ligament reconstruction (ACLR) are not well understood. Purpose: To examine the progression of knee OA and changes in symptoms and function in isolated and combined injuries from 15 to 20 years after ACLR. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 210 subjects with ACLR were prospectively followed. At the 15- and 20-year follow-ups, radiographs were obtained and classified by the Kellgren and Lawrence (K-L) grading system. Symptoms and function were evaluated with the Knee injury and Osteoarthritis Outcome Score (KOOS) as well as isokinetic quadriceps and hamstring muscle strength tests. Results: There were 168 subjects (80%) who returned for the 20-year follow-up, with a mean (±SD) age of 45 ± 9 years, mean body mass index of 27 ± 4, and median Tegner activity level of 4 (range, 0-9). The prevalence of radiographic TF and PF OA at the 20-year follow-up was 42% and 21%, respectively. Patients with ACL injuries and other combined injuries had significantly higher prevalence of radiographic TF OA compared with those who had isolated ACL injury (P < .0001). There was a 13% increase in radiographic TF OA (P = .001) and an 8% increase in PF OA (P = .015) from the 15- to the 20-year follow-up. A significant deterioration in knee symptoms and function was observed on the KOOS subscales (P ≤ .01), with the exception of quality of life (P = .14), as well as a decrease in quadriceps muscle strength and hamstring muscle strength (P < .0001). Conclusion: The prevalence of radiographic TF and PF OA was 42% and 21%, respectively. A significantly higher prevalence of TF OA was found for subjects with combined injuries compared with those who had isolated ACL injury. The majority of the subjects were stable radiographically over the 5 years between follow-ups. A statistically significant deterioration in symptoms and function was noted, but the mean changes were of questionable clinical importance.

Quadriceps Muscle Contraction Protects the Anterior Cruciate Ligament During Anterior Tibial Translation

The proposed skiing injury mechanism that suggests a quadriceps muscle contraction can contribute to ante rior cruciate ligament rupture was biomechanically in vestigated. The effect of quadriceps muscle force on a knee specimen loaded to anterior cruciate ligament failure during anterior tibial translation was studied in a human cadaveric model. In both knees from six do nors, average age 41 years (range, 31 to 65), the joint capsule and ligaments, except the anterior cruciate ligament, were cut. The quadriceps tendon, patella, patellar tendon, and menisci were left intact. One knee from each pair was randomly selected to undergo de structive testing of the anterior cruciate ligament by anterior tibial translation at a displacement rate of 30 mm/sec with a simultaneously applied 889 N quadri ceps muscle force. The knee flexion during testing was 30°. As a control, the contralateral knee was loaded correspondingly, but only 5 N of quadriceps muscle force was applied. The ultimate load for the knee to anterior cruciate ligament failure when tested with 889 N quadriceps muscle force was 22% ± 18% higher than that of knees tested with 5 N of force. The linear stiffness increased by 43% ± 30%. These results did not support the speculation that a quadriceps muscle contraction contributes to anterior cruciate ligament failure. In this model, the quadriceps muscle force protected the anterior cruciate ligament from injury during anterior tibial translation.