Compound nerve action potential of common peroneal nerve and sural nerve action potential in common peroneal neuropathy.

To enhance the accuracy for determining the precise localization, the findings of the compound nerve action potentials (CNAPs) of the common peroneal nerve (CPN) were investigated in patients with common peroneal mononeuropathy (CPM) in the knee, and the sural sensory nerve action potentials (SNAPs) were also analyzed. Twenty-five patients with CPM in the knee were retrospectively reviewed. The findings of the CNAPs of the CPN recorded at the fibular neck and the sural SNAPs were analyzed. The lesion was localized at the fibular head (abnormal CNAPs) and at or distal to the fibular head (normal CNAPs). Seven patients were diagnosed as having a lesion at or distal to the fibular neck, and 18 cases were diagnosed as having a fibular head lesion. The sural SNAPs were normal in all the cases of lesion at or distal to the fibular neck. Among 18 cases of fibular head lesion, the sural SNAPs were normal in 7 patients: two cases of conduction block and 5 cases of mild axon loss. Eleven patients showed abnormal sural SNAPs. Of those, 9 cases were severe axon loss lesions and 2 patients were diagnosed as having severe axon loss with conduction block. The recording of the CNAPs may enhance precise localization of CPM in the knee. Moreover, the sural SNAPs could be affected by severe axonal lesion at the fibular head.

Vertical femoral tunnel placement results in rotational knee laxity after anterior cruciate ligament reconstruction.

PURPOSE: This retrospective study was performed to relate tunnel position as measured by plain radiographs and magnetic resonance imaging (MRI) to residual pivot shift and to determine its clinical relevance after anterior cruciate ligament reconstruction via central quadriceps tendon autograft. METHODS: We reviewed 137 arthroscopic anterior cruciate ligament reconstructions via quadriceps tendon autograft with a minimum of 2 years' follow-up. Clinical results were evaluated by use of the Lachman test, pivot-shift test, Lysholm score, and Cybex dynamometer (Lumex, Ronkonkoma, NY). Anterior tibial translation was measured with the KT-1000 arthrometer (MEDmetric, San Diego, CA). Patients were classified into 3 groups based on postoperative pivot-shift and Lachman test findings: group I, both negative; group II, negative Lachman test and positive pivot shift; and group III, both positive. The radiographic analysis was performed via the angle between the tibial and femoral tunnels on plain anteroposterior radiographs, the angle between the tibial tunnel and anterior tibial cortex on the lateral view, and the femoral and tibial tunnel location by use of the ratio method. Postoperative knee MRI was performed, and the angle between the intercondylar anteroposterior axis and femoral tunnel on the axial view and the angle between the joint line and the graft on the oblique coronal and sagittal views were measured. RESULTS: There were 100 patients in group I, 13 in group II, and 24 in group III. Patients in group I showed the greatest improvement in Lysholm score among the groups, and patients in group III had the greatest side-to-side difference by KT-1000 arthrometer. Tunnel obliquity as measured by the angle between the anteroposterior axis of the femur and the femoral tunnel in the axial view on MRI was greater (P < .05) and the angle between the joint line and the graft on the oblique coronal view was less in group I. CONCLUSIONS: This study showed a significantly lower Lysholm score and more vertical orientation of the femoral tunnel in the group with residual pivot shift than in the group without pivot shift. Vertical orientation of the femoral tunnel in the axial plane is closely related to residual pivot shift without definite anteroposterior laxity. More oblique positioning of the graft may have advantages in rotational stability, which in turn increase subjective patient satisfaction. LEVEL OF EVIDENCE: Level III, diagnostic study of nonconsecutive patients without consistently applied reference gold standard.

Outcome of anterior cruciate ligament reconstruction using quadriceps tendon autograft.

PURPOSE: The purpose of this study was to determine the outcome of anterior cruciate ligament (ACL) reconstruction using a quadriceps tendon autograft. TYPE OF STUDY: A case series of patients who had received arthroscopic ACL reconstructions using quadriceps tendon autograft was retrospectively evaluated. METHODS: Sixty-seven ACL reconstructions were evaluated at a mean of 41 months (range, 27 to 49 months). Clinical assessment was made using a modified Lysholm score, documentation of International Knee Documentation Committee (IKDC), the anterior knee pain questionnaire of Shelbourne and Trumper, and by KT-2000 arthrometric analysis. Isokinetic strength testing and radiographic assessments were also performed. RESULTS: Arthrometric analysis showed that 63 knees (94%) were graded A or B with a median laxity of 2 mm postoperatively. The Lysholm score improved postoperatively from 71 to 90 ( P < or = .05). Extension peak torque of the quadriceps muscle recovered to 82% and 89% of that of the contralateral knee at 180 degrees/second at 1 year and 2 years after surgery, respectively. The patellar position in terms of congruence angle and Insall-Salvati ratio did not show any significant change. Only 4 patients complained of moderate pain on kneeling and 1 patient complained of harvest-site tenderness. CONCLUSIONS: ACL reconstruction using a quadriceps tendon autograft showed satisfactory results with reduced donor-site morbidities. The quadriceps tendon can be a reliable source of graft, and is comparable to bone-patellar tendon-bone or hamstring tendon in ACL reconstruction. LEVEL OF EVIDENCE: Level IV, Case Series (no, or historical, control group).

Glial choristoma in the middle ear and mastoid bone: a case report.

Heterotopic brain tissue usually involves extracranial midline structures of the head and neck such as nose, nasopharynx, and oral cavity. Its occurrence in the non-midline structures, including middle ear, is rare. We described a 50-yr-old-man with heterotopic glial tissue in the middle ear and mastoid bone. The patient presented with progressive hearing loss for 8 yr. There was no history of congenital anomalies, trauma, or ear surgery. Computed tomography revealed a mass-like lesion with soft tissue density occupying the middle ear cavity and mastoid antrum. At the operation, a gray-white fibrotic mass was detected in the epitympanic area. Mesotympanum and ossicles were intact. The patient underwent left simple mastoidectomy with type I tympanoplasty. During operation, definite cranial bone defect or cerebrospinal fluid leakage was not found. Histologically, the lesion was composed of exclusively mature, disorganized glial tissue with fibrovascular elements in a rather loose fibrillary background. Glial tissue showed diffuse positive reaction for glial fibrillar acidic protein and S100 protein on immunohistochemical study.

Posterolateral reconstruction using split Achilles tendon allograft.

Injury to the cruciate ligaments of the knee commonly occurs in association with posterolateral instability, which can cause severe functional disability including varus, posterior translation, and external rotational instability. Failure to diagnose and treat an injury of the posterolateral corner in a patient who has a tear of the cruciate ligament can also result in the failure of the reconstructed cruciate ligament. Unlike isolated posterior cruciate ligament injury, there seems to be a consensus of opinion that injury to the posterolateral corner, whether isolated or combined, is best treated by reconstructing the posterolateral corner along with the coexisting cruciate ligament injury, if combined. Commonly proposed methods of reconstructing the posterolateral corner have focused on the reconstruction of the popliteus, the popliteofibular ligament, and the lateral collateral ligament. We introduce a new technique for reconstructing the posterolateral corner using a split Achilles tendon allograft. Our method reasonably addresses the several pitfalls in the reconstruction of the posterolateral corner, including (1) concurrent reconstruction of important posterolateral structures, (2) regaining the isometry of the lateral collateral ligament, (3) repositioning the reconstructed popliteus into its original position, and (4) providing a secure fixation method.