Reconstruction of the patella with an autogenous iliac graft: clinical and radiologic results in thirteen patients.

PURPOSE: Extension lag, quadriceps weakness and subluxation of the extensor apparatus are known complications of patellectomy. In the case of total knee joint replacement with a nonconstrained system an instability may be encountered. Reconstruction of the patella allows restoration of the moment arm to improve quadriceps leverage. The goal of our study was to analyse the clinical and radiological results after reconstruction of the patella with an autogenous iliac graft. METHODS: 13 previously patellectomized patients had reconstruction of the patella with an autogenous iliac graft and were retrospectively studied by clinical and radiographic examination. For evaluation we used the scores of Feller and the Knee Society. Also, all complications were recorded. RESULTS: After an average follow-up of 40.1 months, nine patients had full strength of the quadriceps, while six had an improved function of the extensor apparatus. The mean Feller score was 21.8 and the Knee Society score was 67.3 for knee and 57.5 for function. Six complications occurred including three infections, two problems with the replaced patella and one fracture of the anterior superior iliac spine. CONCLUSIONS: Reconstruction of the patella with an autogenous iliac graft enables the strength of the extensor apparatus with restoration of the knee joint.

[Muscular torticollis]. / Muskulärer Schiefhals.

OBJECTIVE: Correction of malalignment of the cervical spine with the head tilted to the side of the shortened muscle and rotation to the opposite side due to a contract sternocleidomastoid muscle. Attainment of an increased range of motion of the cervical spine and a better cosmetic appearance. Regression of a facial asymmetry. INDICATIONS: Contract sternocleidomastoid muscle with deformity intolerable by the patients and their parents. CONTRAINDICATIONS: Bony anomalies with consecutive torticollis. Torticollis caused by other muscular contractures (trapezoid muscle). Torticollis due to acute rheumatoid arthritis or other inflammation around the neck. Other forms of torticollis (psychogenic, ocular, vestibular or spasmodic torticollis). SURGICAL TECHNIQUE: In younger children, subcutaneous tenotomy of the distal part of the sternocleidomastoid muscle. At preschool age, additional incision of the deep cervical fascial layer with an open tenotomy. In delayed operations, open distal and proximal tenotomy together with incision of the deep fascial layer or complete excision of the sternocleidomastoid muscle. POSTOPERATIVE MANAGEMENT: Until the age of 6 years, application of a Minerva cast after surgery for 6 weeks. Subsequently, physical therapy for 6 months. In children of school age and older people, application of a soft cervical bandage for 6 weeks with functional physiotherapy. RESULTS: In 83 reexamined patients with muscular torticollis, 76 biterminal and seven distal tenotomies had been performed. Regarding the age at the time of operation and the interval to follow-up, an improvement of facial symmetry could be achieved. At the control, 25 patients showed complete recovery of facial asymmetry, 43 had a slight and 15 a severe asymmetry. The complication rate was low with one injury to the external jugular vein and one transient facial nerve paresis. In two patients, passive overcorrection in the cast resulted in transient paresis. Two patients developed a recurrence of muscular torticollis.

Influence of an infrapatellar fat pad edema on patellofemoral biomechanics and knee kinematics: a possible relation to the anterior knee pain syndrome.

INTRODUCTION: An edema of the infrapatellar fat pad following knee arthroscopy or in case of chronic anterior knee pain syndrome is suspected to increase the patellofemoral pressure by a modification of the patellofemoral glide mechanism. The study was performed to evaluate this hypothesis. MATERIALS AND METHODS: Isokinetic knee extension from 120 degrees of flexion to full extension was simulated on 10 human knee cadaver specimens (six males, four females, average age at death 42 years) using a knee kinemator. Joint kinematics was evaluated by ultrasound sensors (CMS 100, Zebris, Isny, Germany), and retro-patellar contact pressure was measured using a thin-film resistive ink pressure system (K-Scan 4000, Tekscan, Boston). Infrapatellar tissue pressure was analyzed using a closed sensor cell which was implanted inside the fat pad (GISMA, Buggingen, Germany). An inflatable fluid cell was implanted by ultrasound control in the center of the infrapatellar fat pad and filled subsequently with water to simulate a fat pad edema. All parameters were recorded and analyzed from 0 to 5 ml volume of the fluid cell. RESULTS: Simulating a fat pad edema resulted in a significant (P < 0.01) increase of the infrapatellar fat pad pressure (247 mbar at 0 ml to 615 mbar at 5 ml volume). In knee extension and flexion the patella flexion (sagittal plane) was decreased while we did not find any other significant influence of the edema on knee kinematics. During the analysis of the patellofemoral biomechanics, a simulated fat pad edema resulted in a significant (P < 0.05) decrease of the patellofemoral force between 120 degrees of knee flexion and full extension. The contact area was reduced significantly near extension (0 degree-30 degrees) by an average of 10% while the contact pressure was reduced at the entire range of motion up to 20%. CONCLUSION: An edema of the infrapatellar fat pad does not cause an increase of the patellofemoral pressure or a significant alteration of the patellofemoral glide mechanism. Anterior knee pain in case of a fat pad edema may be related to a significant increase of the tissue pressure and possible histochemical reactions.

The effect of tourniquet release timing on perioperative blood loss in simultaneous bilateral cemented total knee arthroplasty: a prospective randomized study.

Today the use of pneumatic tourniquet is commonly accepted in total knee arthroplasty (TKA) to reduce perioperative blood loss. There are a few prospective randomised and nonrandomised studies that compare the effect of tourniquet release timing in cementless or cemented unilateral TKA. However, many of these studies show an inadequate reporting and methodology. This randomized prospective study was designed to investigate the efficiency of tourniquet release timing in preventing perioperative blood loss in a simultaneous bilateral TKA study design. To our knowledge, this is the first study of its kind, in which the effect of tourniquet release timing on perioperative blood loss was investigated in simultaneous bilateral cemented TKA to compare both techniques intraindividually. In 20 patients (40 knees) one knee was operated with tourniquet release and hemostasis before wound closure, and the other knee with tourniquet release after wound closure and pressure dressing. We found no significant difference in total blood loss between both techniques (p=0.930), but a significant difference in operating time (p=0.035). There were no postoperative complications at a follow-up of 6 month. Other studies report an increase the blood loss in early tourniquet release and an increase the risk of early postoperative complications in deflation of tourniquet after wound closure. In this study we found no significant difference in perioperative blood loss and no increase of postoperative complications. Therefore, we recommend a tourniquet release after wound closure to reduce the duration of TKA procedure and to avoid possible risks of extended anaesthesia.

The influence of nonanatomical insertion and incongruence of meniscal transplants on the articular cartilage in an ovine model.

BACKGROUND: Adequate size matching and anatomically correct positioning must be recognized as essential factors influencing the outcome of meniscal transplantation. HYPOTHESIS: Nonanatomical insertion and incongruence of meniscal transplants has an influence on the development of degenerative changes. STUDY DESIGN: Controlled laboratory study. METHODS: Ten female sheep were used for this animal study. Both knees (N = 20) were divided into 3 groups, subjected to either meniscectomy (group I; n = 10), to a medial meniscal autograft transplantation with a nonanatomical insertion of the anterior and posterior horn (group II; n = 5), or a meniscal autograft transplantation from the opposite knee as an incongruent meniscal autograft (group III; n = 5). After 6 months, radiographic (Fairbank's criteria), macroscopic (Jackson score), and histological evaluation by light microscopy (Mankin score) and scanning electron microscopy of the articular cartilage was performed. RESULTS: All applied evaluation methods demonstrated that nonanatomical insertion of meniscal transplants resulted in the highest amount of degenerative cartilage changes. The histological assessment even revealed a significantly enlarged cartilage damage for the non-anatomic-positioned meniscal transplants in relation to the meniscectomized knees. Furthermore, the incongruent meniscal transplants demonstrated a significantly better cartilage situation than nonanatomically inserted meniscal transplants. CONCLUSION: The histological evaluation demonstrated clearly that a nonanatomically inserted meniscal transplant leads to degenerative cartilage changes that are worse than that after meniscectomy. CLINICAL RELEVANCE: Precise anatomic positioning is mandatory for the potential chondroprotective effect of meniscal transplants.

[Reconstruction of the medial patellofemoral ligament by tunnel transfer of the semitendinosus tendon]. / Die Rekonstruktion des medialen patellofemoralen Ligaments mit der getunnelten Semitendinosussehne.

OBJECTIVE: Stabilization of the patella by reconstruction of the medial patellofemoral ligament. INDICATIONS: Chronic recurrent lateral dislocation or subluxation of the patella. Habitual lateral dislocation of the patella. CONTRAINDICATIONS: Primary dislocation of the patella. Genu valgum with a Q-angle > 15 degrees . Status following semitendinosus tendon transfer to reconstruct the anterior cruciate ligament. Joint infection. Neurogenic instability, ischiocrural muscle deficiency. SURGICAL TECHNIQUE: Division of the distal insertion of the semitendinosus muscle at the pes anserinus. Subligamentous tunneling at the proximal insertion of the medial collateral ligament. The distal end of the semitendinosus tendon is transferred through the subligamentous tunnel to the medial patellar margin. Fixation of the tendon to the medioproximal patellar margin by passing it through an oblique transpatellar drill hole. RESULTS: The patella was stabilized by dynamic reconstruction of the medial patellofemoral ligament in 14 patients with chronic recurrent or habitual lateral patellar dislocation. Ten patients were available for clinical follow-up assessment at an average of 13 months (8-27 months) postoperatively. The postoperative Kujala Index (maximum 100 points) increased on average from 56 to 95 points.

Twenty-year results of combined meniscal allograft transplantation, anterior cruciate ligament reconstruction and advancement of the medial collateral ligament.

The purpose of this study was to determine the objective and subjective long-term outcomes of the first free meniscal allograft transplantations in five patients with complete absence or non-repairable lesion of the medial meniscus after 20 years. Between 1984 and 1986 five patients underwent concomitant medial meniscal transplantation with a deep frozen meniscal allograft, ACL reconstruction and femoral advancement or temporary detachment of the MCL. The clinical outcome of the patients was evaluated 20 years postoperatively using clinical assessment, Lysholm-score, KOOS, IKDC-score, radiographs and magnetic resonance imaging. The Lysholm-score ranged between 21 and 97 points of 100 maximal available points. Corresponding to this the total KOOS ranged between 28.4 and 91.1%. The results of the IKDC-score were evaluated as nearly normal (B) (n = 2), abnormal (C) (n = 2) and severely abnormal (D) (n = 1). The radiological evaluation according to the Kellgren-Lawrence classification showed an increase of the degenerative changes between one and four grades. The radiological results revealed clear degenerative changes with long-term follow-up after meniscal allograft transplantation even though some patients did relatively well regarding the subjective and clinical results in the 20-year follow-up examination in comparison with the literature. Despite these relative clear results the question if medial meniscal transplantation can protect against development of arthritis cannot definitely be answered because in this first case series some aspects of meniscus transplantation that have not been considered which turned out to be of importance during the last 20 years. Furthermore, it has to be taken into account that all patients revealed a cartilage damage at the time of surgery and an ACL reconstruction was performed in addition. Nevertheless from biomechanical point of view it might be taken into consideration to combine the medial meniscus transplantation at least with a high tibial osteotomy. Level of evidence was (IV, case series).

In vitro measurement of patellar kinematics following reconstruction of the medial patellofemoral ligament.

This study compares the effects of two different techniques of medial patellofemoral ligament (MPFL) reconstruction, and proximal soft tissue realignment on patellar stabilization against lateral dislocation. Eight human cadaver knee specimens with no radiological pathomorpholgy on a straight lateral view, contributing to patellofemoral instability, were mounted in a kinematic knee simulator and isokinetic extension was simulated. Patellar kinematics were measured with an ultrasound positioning system (zebris) while a 100 N laterally directed force was applied to the patella. The kinematics were compared with intact knee conditions under MPFL deficient conditions, as well as following dynamic reconstruction of the MPFL using a distal transfer of the semitendinosus tendon, following static reconstruction by a semitendinosus autograft, and following proximal soft tissue realignment of the patella (Insall procedure). Dynamic reconstruction of the MPFL resulted in no significant alteration (P = 0.16) of patellar kinematics. Static reconstruction of the MPFL significantly medialized (P < 0.01) the patellar movement without, but restored intact knee kinematics under the laterally directed force. In contrast, following proximal soft tissue realignment, the patellar movement was constantly medialized and internally tilted (P = 0.04). Dynamic and static reconstruction of the MPFL create sufficient stabilization of the patella. Following proximal soft tissue realignment, the patellar position was over-medialized relative to intact knee conditions, which could lead to an overuse of the medial retropatellar cartilage.

Dynamic measurement of patellofemoral contact pressure following reconstruction of the medial patellofemoral ligament: an in vitro study.

BACKGROUND: Surgical reconstruction of the medial patellofemoral ligament used to stabilize the patella against lateral dislocation may concomitantly produce alteration of the patellofemoral contact pressure distribution. Two different tendon transfer techniques of reconstructing the medial patellofemoral ligament, one dynamic and one static, as well as a proximal soft tissue realignment of the patella were investigated. METHODS: Eight human knee specimens were mounted in a kinematic knee simulator and isokinetic extension motion was simulated. Patellofemoral pressure was measured using a pressure sensitive film while a 100 N laterally directed dislocation load was applied to the patella. The specimens were evaluated in a physiologic state, as well as after dynamic reconstruction of the medial patellofemoral ligament using a distal transfer of the semitendinosus tendon, following static reconstruction using a semitendinosus autograft, and following proximal soft tissue realignment of the patella. FINDINGS: Following both reconstruction techniques of the medial patellofemoral ligament patellofemoral contact pressure was not significantly (P=0.49) altered. In contrast, after proximal realignment a trend (P=0.07) towards higher contact pressure near knee extension was observed. In the absence of a lateral dislocation load dynamic and static reconstruction resulted in a medialization (P=0.04) of the center of pressure, whereas under the application of a 100 N dislocation load the center of pressure showed no significant alteration. Following proximal realignment the center of pressure was significantly medialized without (P<0.01) and with a dislocation load (P=0.01) throughout the entire range of knee motion. INTERPRETATION: Static and dynamic ligament reconstruction of the medial patellofemoral ligament did not alter patellofemoral pressure. Proximal realignment, on the other hand, resulted in a constant medialization of the patellofemoral pressure. The data suggest that the reconstruction techniques would be associated with a low risk of causing premature cartilage degeneration due to excessive patellofemoral contact pressure, whereas proximal realignment could cause medial overload of the patellofemoral joint.

Improved implantation technique for resurfacing arthroplasty of the hip.

OBJECTIVE: Prevention of incorrect positioning of the surface replacement, whereby the center of the femoral head for the implantation of the replacement surface is ascertained by central drilling of the femoral neck under image intensifier control. INDICATIONS: An arthritically damaged, but not too severely deformed femoral head that can be reamed without injuring the femoral neck. CONTRAINDICATIONS: Hip ankylosis. Femoral head necrosis. Severe deformity of the femoral head. State after varus osteotomy. SURGICAL TECHNIQUE: Using a 6-mm drill bit, the femoral neck of the affected hip is drilled from lateral to medial under anteroposterior and lateral imaging deliberately perforating the femoral head. The hip joint is exposed through a minimized invasive anterolateral, lateral, or posterior approach and dislocated. A guide rod corresponding in size to the 6-mm drill channel is inserted into the drill hole; it serves as a guide for all subsequent preparations of the femoral head, depending on the type of prosthesis. After implantation of the corresponding acetabular component, resurfacing of the femoral head is done. Reduction of the joint completes surgery. RESULTS: In the first 14 hips the midpoint of the femoral head was ascertained by using the manufacturer's centering device. In 31 subsequent hips the midpoint of the femoral head was found by central drilling of the femoral neck. Using the centering device, the average deviation of the angle of the prosthesis from the preoperative CCD angle was 7 degrees (+/- 5.7 degrees ); for central drilling of the femoral neck it was only 3 degrees (+/- 3.4 degrees ). The exact alignment of the resurfacing component is crucial for the success of surgery. It is achieved with greater precision with central drilling of the neck than with the manufacturer's centering device.

In vitro investigation of the effect of medial patellofemoral ligament reconstruction and medial tibial tuberosity transfer on lateral patellar stability.

PURPOSE: Two different operative techniques for stabilizing the patella against lateral displacement movement were investigated. TYPE OF STUDY: In vitro experimental study. METHODS: Five human cadaver knee specimens with a normal Q-angle were mounted in a kinematic knee simulator and investigated under simulated isokinetic extension motions. Patellar movement was measured while a 100-N laterally directed subluxation load was applied to the patella. Ligament loading of the medial patellofemoral ligament was measured using a strain gauge based buckle transducer inserted in the fibers of the ligament. The knee was evaluated in an intact physiologic state, as well as after medial transfer of the tibial tuberosity, and after the medial patellofemoral ligament was transected and reconstructed using a hamstring autograft. RESULTS: A significant reduction in lateral displacement and ligament load was observed with the use of the hamstring autograft reconstruction compared with the medial transfer of the tibial tuberosity. CONCLUSIONS: Medial transfer of the tibial tuberosity showed no significant relief of ligament loading and stabilizing effect on patellar movement, whereas reconstruction of the medial patellofemoral ligament showed a significant stabilizing effect on patellar movement. CLINICAL RELEVANCE: In cadaver specimens, we evaluated the effect of tibial tubercle transfer and the patellofemoral ligament and found that reconstruction of the patellofemoral ligament alone was sufficient to restore stability in a cadaveric model. Additionally, we found that the flexion angle had little effect on the loading of the medial patellofemoral ligament autograft, which would support early mobilization of patients after surgery. We found that the graft was not unduly loaded.

The popliteal cyst.

A popliteal cyst, originally called Baker's cyst, is a synovial fluid-filled mass located in the popliteal fossa. The most common synovial popliteal cyst is considered to be a distension of the bursa located beneath the medial head of the gastrocnemius muscle. Usually, in an adult patient, an underlying intra-articular disorder is present. In children, the cyst can be isolated and the knee joint normal. The anatomy, etiopathogenesis, clinical presentation, differential diagnosis, imaging and treatment modalities of the popliteal cyst are presented. The authors try to answer some questions dealing with this condition. Is the cyst isolated, can it be treated as such, is its origin always well-defined and does surgical excision provide a permanent cure?

Distribution of substance-P nerves inside the infrapatellar fat pad and the adjacent synovial tissue: a neurohistological approach to anterior knee pain syndrome.

INTRODUCTION: The purpose of the study was to determine the distribution and number of nerves inside the infrapatellar fat pad and the adjacent synovium, in particular with regards to nociceptive substance-P nerves. MATERIALS AND METHODS: The infrapatellar fat pad of the knee was resected from 21 patients (4 male, 17 female, mean age 69 years) during the course of standard total knee arthroplasty operations performed in our clinic. The fat pad was dissected into five standardized segments, fixed in formalin and embedded in paraffin. Immunohistochemical techniques using antibodies against S-100 protein and substance-P (SP) were employed to determine and specify the nerves. RESULTS: Studying all the detectable nerves present in 50 observation fields (200-fold magnification), we found an average of 106 S-100 versus 25 SP nerves (24%) in the synovium and 27 S-100- versus 7 SP nerves (26%) in the interior of the fat pad. The total nerve count was significantly (P < 0.001) higher in the synovium than in the fat pad for both marker types. The number of S-100 nerves was significantly (P < 0.05) higher in the central and lateral segments of the fat pad, while SP nerves were equally distributed throughout all segments of the fat-pad. SP nerves were significantly more frequently associated with blood vessels inside the fat pad (43%, P < 0.05) than in the synovial tissue (28%). CONCLUSION: The occurrence and distribution of SP nerves inside the infrapatellar fat pad suggest a nociceptive function and a neurohistological role in anterior knee pain syndrome. The data support the hypothesis that a neurogenous infection of the infrapatellar fat pad could contribute to anterior knee pain syndrome.

Infrapatellar fat pad pressure and volume changes of the anterior compartment during knee motion: possible clinical consequences to the anterior knee pain syndrome.

This biomechanical study was performed to measure tissue pressure in the infrapatellar fat pad and the volume changes of the anterior knee compartment during knee flexion-extension motion. Knee motion from 120 degrees of flexion to full extension was simulated on ten fresh frozen human knee specimens (six from males, four from females, average age 44 years) using a hydraulic kinematic simulator (30, 40, and 50 Nm extension moment). Infrapatellar tissue pressure was measured using a closed cell sensor. Infrapatellar volume change in the anterior knee compartment was evaluated subsequent to removal of the fat pad using a water-filled bladder. We found a significant increase of the infrapatellar tissue pressure during knee flexion, at flexion angles of <20 degrees and >100 degrees . The average tissue pressure ranged from 343 (+/-223) mbar at 0 degrees to 60 (+/-64) mbar at 60 degrees of flexion. The smallest volume in the anterior knee compartment was measured at full extension and 120 degrees of flexion, whereas the maximum volume was observed at 50 degrees of flexion. In conclusion, the data suggest a biomechanical function of the infrapatellar fat pad at flexion angles of <20 degrees and >100 degrees , which suggests a role of the infrapatellar fat pad in stabilizing the patella in the extremes of knee motion.

Shoulder arthrodesis: indications, technique, results, and complications.

Complications after shoulder arthrodesis are frequent. Through results and comparisons with the literature, the presented article analyzes the correlation of complications with the specific operative techniques, indications, and postoperative treatment. Between 1964 and 2001, a total of 43 cases of shoulder arthrodesis (13 screw and 30 plate arthrodeses) were performed and then analyzed after a mean of 6.7 years (range, 0.5-36 years). Surgery was carried out on 10 female patients (23%) and 33 male patients (77%) with a mean age of 35 years (range, 11-82 years). These patients had the following indications: paralysis (32 [74%]), osteoarthritis or humeral head necrosis (15 [35%]), infection (7 [16%]), and persistent shoulder instability (6 [14%]). The extent of active movement after arthrodesis was 56 degrees abduction (range, 20 degrees - 90 degrees) and 60 degrees forward flexion (range, 20 degrees - 105 degrees), with an increase in the Constant score in all cases, from a mean of 27 points preoperatively to 57 points postoperatively (difference, 30 points). The patients rated the outcome of surgery as excellent, good, or satisfactory in 91% of cases. Complications after shoulder arthrodesis were noted in 12 of 43 patients (28%). The most frequent complications after screw/plate arthrodesis included pseudarthrosis, 2 (15%)/3 (10%); infection, 1 (8%)/4 (13%); and fracture of the humerus, 0/4 (13%). No specific judgment can be attributed to the different osteosynthesis techniques used in shoulder arthrodesis, either in the cases presented at our clinic or in the literature. Pseudarthrosis appeared to be less frequent in cases of plate arthrodesis compared with screw arthrodesis. However, the application of plates resulted more often in infection, postoperative fractures of the humerus, and the necessity for removal of material. Particularly in patients with paralysis, a shoulder arthrodesis resulted in an improvement in postoperative active function and presented a suitable operative option.

Primary stability of shoulder arthrodesis using cannulated cancellous screws.

There are no biomechanical studies available concerned with the primary stability of shoulder arthrodesis. The aim of our biomechanical investigations was to ascertain a minimal material combination with high primary stability for shoulder arthrodesis. For that purpose, the primary stability of 6 different forms of screw arthrodesis was investigated under the stress of abduction, adduction, anteversion, and retroversion. The mean values of the screw arthrodeses were compared with those of a 16-hole plate arthrodesis. All tests were carried out on 24 human specimens without destruction by use of a materials testing machine. The most stable form of screw arthrodesis for the load directions of abduction, adduction, anteversion, and retroversion results from a specific configuration of screws comprising 3 horizontal humeroglenoid screws and 3 vertical acromiohumeral screws (318.5 +/- 99.0 N). For three forms of arthrodesis, each with 3 humerus-glenoid screws (299.9 +/- 95.4 N), no significant difference (P = .530) was found compared with a 16-hole plate arthrodesis (293.4 +/- 89.3 N). The plate arthrodeses only achieved higher power values on abduction and adduction stress in comparison with screw arthrodesis with 3 humerus-glenoid screws. The difference was insignificant. Because arthrodesis with 3 humerus-glenoid screws was significantly more stable on stress of anteversion and retroversion, this particular screw arthrodesis is considered superior to plate arthrodeses. The use of the most stable form of screw arthrodesis may reduce nonunion.

Biomechanical and kinematic influences of a total infrapatellar fat pad resection on the knee.

BACKGROUND: This biomechanical study was performed to evaluate the consequences of total infrapatellar fat pad resection on knee kinematics and patellar contact pressure. HYPOTHESIS: Resection of the infrapatellar fat pad produces significant changes in knee kinematics and patellar contact pressure. STUDY DESIGN: Biomechanical cadaveric study. METHODS: Isokinetic knee extension was simulated on 10 human knee cadaveric specimens (6 men, 4 women; mean age at death, 44 years). Joint kinematics were evaluated by an ultrasound-based 3D motion analysis system, and retro-patellar contact pressure was measured using an electronic pressure-sensitive film. All data were taken before and after resection of the infrapatellar fat pad and statistically analyzed. RESULTS: A total resection of the infrapatellar fat pad resulted in a significant decrease of the tibial external rotation relative to the femur between 63 degrees of flexion and full knee extension (maximum: 3 degrees rotation difference at 0 degrees knee flexion, P = .011), combined with a significant medial translation of the patella between 29 degrees and 69 degrees of knee flexion (range, 0.9-1.3 mm, P = .017-.028). Retro-patellar contact pressure was significantly reduced (from 20% to 25%, P = .008-.021) at all flexion angles. CONCLUSION: A resection of the infrapatellar fat influences patellar biomechanics and knee kinematics. CLINICAL RELEVANCE: The infrapatellar fat pad may have a biomechanical function and may play a role in anterior knee pain syndrome.

Reconstructive operations for the upper limb after brachial plexus palsy.

Limited function due to paralysis following brachial plexus lesions can be improved by secondary operations of the bony and soft tissue. Between April 1994 and December 2000, 109 patients suffering from arm-plexus lesions underwent a total of 144 reconstructive operations guided by our concept of integrated therapy. The average age at the time of surgery was 32 years (range: 15-59). The following operations were performed: shoulder arthrodesis (23), trapezius transfer (74), rotation osteotomy of humerus (9), triceps to biceps transposition (9), transposition of forearm flexors or extensors (8), latissimus transfer (7), pectoralis transfer (1), teres major transfer (1), transposition of flexor carpi ulnaris to the tendons of extensor digitorum (10), and wrist arthrodesis (2). Prospectively, in all patients, the grade of muscle power of the affected upper extremity was evaluated prior to surgery. The follow-up period for all 144 operations was, on average, 22 months (range: 6-74). By means of operative measures, almost all patients obtained an improvement of shoulder function (100%) and stability (>90%), elbow flexion (85%), and hand, finger, and thumb (100%). When muscles malfunction after brachial plexus lesions, one should take into account the individual neuromuscular defect, passive joint function, and bony deformities; different procedures such as muscle transpositions, arthrodeses, and corrective osteotomies can then be performed to improve function of the upper extremity. Each form of operative treatment presents patients with certain benefits and all are integrated into a total treatment plan for the affected extremity.