Lanny L. Johnson

Osteochondritis dissecans of the knee: Arthroscopic compression screw fixation

This article describes repair of osteochondritis dissecans of the knee by arthroscopic compression screw fixation and reports the healing response and clinical result. Diagnostic and operative arthroscopy was performed. Compression screw fixation was used. The exact operative technique varied depending on the status of the lesion. The patients were non-weight bearing for 2 months, after which a second surgery was necessary for removal of the metallic screw(s). The initial healing response was assessed by the firmness of the lesion to palpation at the second look. Subsequent x-ray evidence of healing was correlated with the clinical outcome. Ninety-four percent of the knees were determined to be initially healed at the time of the second look. Four of these apparently solid repairs subsequently loosened and required repeat surgery. Eighty-eight percent of the patients assessed their results as excellent or good after 2 years minimum follow-up. Arthroscopic compression screw fixation is an effective method of repair for mild to moderately severe cases of osteochondritis dissecans.

Metal and biodegradable interference screws: Comparison of failure strength

The purpose of this laboratory investigation was to determine if there was any difference in the force required to pull out a patellar bone-tendon-bone graft from a femoral bone tunnel when secured by an interference screw of different materials, metal or biodegradable. The tibial end of the bone-tendon-bone graft was placed in the femoral tunnel. A 9-mm metal interference screw was used on the left side, and a 9-mm biodegradable screw was used on the right to secure the graft. Ultimate load to failure was determined by Instron testing. The average load before failure for the graft secured by the metal screw was 436 Newtons and for the biodegradable screw was 565 Newtons. A statistical significance was not demonstrated because there was wide range of loads between donor specimens, probably because of variations in bone density.

Arthroscopic observations before and after manipulation of frozen shoulder

The purpose of this article is to report the arthroscopic findings before and immediately after manipulation for frozen shoulder. Twenty patients were selected for manipulation under general anesthesia after failing to improve with conservative measures in 6 months. The findings showed the joint capsule was difficult to penetrate with the arthroscope cannula and obturator because of the thickness of the capsular tissue. The glenohumeral joint accepted less than the normal amount of fluid. The humeral head was tight against the glenoid even in the suspended position. The main intraarticular finding was vascular synovitis. There were no intraarticular adhesions or degenerative changes. An immediate postmanipulation second-look arthroscopy showed there was synovial and capsular hemorrhage indicative of tearing from the manipulation. After glenohumeral manipulation, the joint accepted more fluid, and the humerus was easily distracted away from the glenoid with intraarticular distention.

Lateral capsular ligament complex: anatomical and surgical considerations

Acute avulsion of the bony attachment of the lateral capsular ligament was observed on x-ray films in September 1975. Seven instances were confirmed at surgery during the following 29- month period. The avulsion was reproduced in six amputation specimens which were dissected to identify the components of the lateral capsular complex. Dynamic studies were performed on a set of amputation specimens to determine the role of the various structures contributing to lateral rotary instability. The dissection revealed that the lateral capsular ligament complex has vertical and horizontal components. The dynamic studies showed that lateral pivot shift was produced by a lateral capsular release, a complete section of the anterior cruciate ligament, and a partial tibial collateral ligament release. Based on these observations, 30 patients have subsequently had re constructive surgery to eliminate their lateral rotational insta bility. In the reconstructive procedure, both the bony attach ment of the lateral capsular ligament and the iliotibial tract with Gerdys tubercle have been moved anteriorly and inferiorly without separating their interconnections or any attachments. Clinical experience in these 30 patients supports the evidence obtained in the dynamic studies. Restoration of stability is secure when both the lateral capsular ligament and the iliotibial tract are advanced with their anatomical connections intact.

The outcome of a free autogenous semitendinosus tendon graft in human anterior cruciate reconstructive surgery: A histological study

This report illustrates the outcome of a free human autogenous semitendinosus tendon graft placed in the knee under arthroscopic control for anterior cruciate ligament reconstruction. The tendon graft showed signs of injury by localized loss of normal histochemical staining properties. The cellularity was not diminished in an early (3-week) specimen. The resultant composite anterior cruciate ligament consisted of two distinct areas: tendon graft and surrounding fibrous tissue. The tendon maintained gross and microscopic characteristics of the original tendon. The tissue surrounding the tendon graft had a disorganized cellular pattern and hypervascularity. The tendon graft in this study did not show gross or microscopic evidence of death and reorganization. Previous reports have led to erroneous conclusions concerning the outcome of a free tendon graft due to inaccurate biopsy site of the reorganizing fibrous tissue surrounding the tendon graft.

The effect of bone compaction on early fixation of porous-coated implants.

The effect of a bone compaction technique versus conventional drilling on the early fixation of porous-coated implants was examined in a canine model. Compaction dilation resulted in a significant increase in implant fixation stiffness (P < .01) and ultimate fixation strength (P < .01) at 0 and 3 weeks. Fixation stiffness remained significantly increased at 6 weeks (P < .01); however, the ultimate fixation strength was not statistically significant between the 2 techniques (P > .05). There was no significant difference in either fixation value at 9 weeks (P > .05). Histological examination of the bone-implant interface demonstrated an increase in the density of cancellous bone immediately adjacent to the implants placed in the compaction dilated holes. The results of this study suggest that the compaction method of host bone preparation may optimize the initial stability of the implant interface of porous-coated prostheses.

The popliteal bursa (Baker's cyst): An arthroscopic perspective and the epidemiology

The purpose of this study was to establish the incidence of the anatomic structure, the popliteal bursa, in patients undergoing arthroscopy and to determine the relationship to associated clinical and pathological factors. Diagnostic arthroscopy was used to identify the presence of the popliteal bursa in 187 consecutive patients (195 knees). Thirty-seven percent of knees had a popliteal bursa identified by the communication with the posterior medial compartment. The cause of the popliteal bursa was not established by this study. This study refuted the causes proposed by others. The existing erroneous conclusions concerning the cause of the popliteal bursa were probably attributable to the failure to recognize the common continuity of the bursa and the knee joint. When the popliteal bursa is present (37%), it becomes symptomatic by responding to the intraarticular disease because of its continuity with the knee joint.

Characteristics of the immediate postarthroscopic blood clot formation in the knee joint

The immediate postoperative bleeding and blood clot formation was observed in 26 human knee joints following a variety of arthroscopic surgical procedures. Observations were made following lavage with lactated Ringers and normal saline solutions. Bleeding occurred from all incised vascular tissue. Blood clot accumulated after each solution within 5 min following tourniquet release and decompression of the joint. Most of the blood clot remained unattached within the joint cavity. Blood clot did attach to all surgically incised or excised surfaces. The clinical relevance of these observations is related to the potential role of the blood clot in intraarticular tissue repair following arthroscopic surgery.

Autogenous Tendon Graft Substitution for Absent Knee Joint Meniscus: A Pilot Study

The purpose of this pilot study was to explore the potential of an autogenous tendon graft to substitute for an absent human knee joint meniscus. Based on the results of animal studies and human reports, it was hypothesized that autogenous tendon tissue would substitute for human knee joint meniscus: maintain mechanical integrity, convert to fibrocartilage, preserve the joint compartment, and provide symptomatic relief for the patient. Five patients, 2 men and 3 women, average age 41 years, had surgical absence of the lateral meniscus, genu valgum, and severe degenerative arthritis of the lateral compartment, but a stable knee. All patients were offered alternative treatments: do nothing, medication, arthroscopic debridement, osteotomy, and knee replacement. The operations were performed by arthroscopy. An accompanying arthroscopic debridement procedure was performed in the same compartment. In 4 cases, the donor graft was the semitendinosus tendon. In 1, the patellar tendon was used because the semitendinosus had been previously used in an anterior cruciate ligament reconstruction. Four of the 5 patients had a second-look arthroscopy and biopsy between 9 and 24 months. There was partial physical integrity to the tendon graft. The tendon graft did not completely convert to fibrocartilage. The joint surface was not preserved. Only 1 patient had minimal clinical improvement; the others were not improved. No patient was made worse. One patient had a total knee replacement 1 year later. Another had a knee fusion after 4 years. All other patients are considering future reconstructive surgery. The autogenous tendon graft as used in this pilot study was not successful as a substitute for an absent meniscus. The hypothesis was not realized. The observations from this pilot study should be helpful in future study protocol design.

Effects of holmium: YAG laser on equine articular cartilage and subchondral bone adjacent to traumatic lesions: A histopathological assessment

This study was performed to investigate the effects of holmium:yttrium-aluminum-garnet (Ho:YAG) laser energy on articular cartilage and subchondral bone adjacent to traumatically created cartilage lesions in a continuous weight-bearing model. The 2.1-microns wavelength was delivered efficiently and precisely in hand-controlled contact and near-contact hard tissue arthroscopic surgery in a saline medium. Bilateral arthroscopy was performed on normal antebrachiocarpal and intercarpal joints of four adult horses. One hundred twenty traumatic lesions were created on three weight-bearing articular surfaces with a knife, curet, or motorized burr. Depths of the lesions were partial and full thickness. Configurations of the lesions were lacerations, scrapes, and craters. Left limbs were used as controls. Right limb lesions were treated with various intensities of laser energy: 0.1. 0.16, and 0.2 J. Animals were killed at intervals of 1, 3, and 8 weeks. Gross microscopic anatomy was documented, and tissue sections were subjected to blind review by a pathologist. Mankin grading for cellularity and proteoglycan content was used to qualitatively evaluate cartilage response. Cartilage adjacent to all lesions exposed to laser energy had better cellularity and proteoglycan content (p < 0.05) than did corresponding controls by Mankin grading. Mankin grades for levels of 0.16 and 0.2 J were lower (p < 0.05) than were those of controls or lesions exposed to 0.1 J. There was loss of cellularity and necrosis in subchondral bone at higher energy levels (0.16 and 0.2 J). This study examined the effects of Ho:YAG laser on articular cartilage and subchondral bone in terms of depth of damage and healing response over time in a weight-bearing model. Additional research to define dose-response curves for Ho:YAG laser treatment of cartilage and subchondral bone are indicated.