Deryk G. Jones

Autologous chondrocyte implantation

Currently, autologous chondrocyte implantation (ACI) is ideally indicated for symptomatic ICRS grade III-IV lesions greater than 2 cm2 along the femoral condyle or trochlear regions. High-demand patients between the ages of 15 to 55 years of age with excellent motivation and compliance potential should be chosen. Lars Peterson assessed his first 101 patients at intermediate to long-term follow-up. Good to excellent clinical results were seen in 92% of the isolated femoral condylar lesions, while these results decreased to 67% in patients with multiple lesions. Osteochondritis dissecans lesions demostrated 89% good-to-excellent results, and in contrast to the initial series patellar lesions did relatively well with 65% good-to-excellent results. Histologic analysis of the matrix in 37 biopsy specimens assessing for type II collagen showed a correlation between hyaline-like repair tissue and good-to-excellent clinical results. Scott Gillogly evaluated 112 patients with 139 defects treated with the ACI procedure over a 5-year period of time. Average size of the defect was 5.7 cm2 with over 60% of patients having failed at least one prior procedure. According to the clinician evaluation portion of the Modified Cincinnati Scale 93% demonstrated good-to-excellent outcomes, while the patient evaluation portion demonstrated 89% good-to-excellent outcomes. This chapter will describe the technique of ACI first reported by the senior author (LP) in 1994, as well as additional methods to deal with the various complex problems that can arise during these demanding procedures. A further review of the current literature supporting this techique as well as those studies that compare ACI to other accepted treatment options will be undertaken as well. In addition, we will review and discuss developing literature supporting current use of various matrices in combination with autologous chondrocytes to treat this difficult patient population.

Improved cartilage repair after treatment with low-intensity pulsed ultrasound.

Low-intensity pulsed ultrasound accelerates bone healing via upregulation of cartilage formation and maturation phases of endchondral bone formation. The current authors evaluated the effect of ultrasound therapy on the repair of full-thickness osteochondral defects. Bilateral, 3.2 mm diameter by 5.0 mm deep osteochondral defects were created in the patellar groove of 106 adult male New Zealand rabbits. The defects were treated with daily low-intensity pulsed ultrasound therapy on the right knee. The left knee was not treated. In Part I, the effect of ultrasound therapy was evaluated at 4, 8, 12, 24, and 52 weeks after surgery. In Part II, the effect of the length of treatment (5, 10, or 40 minutes of daily ultrasound therapy) compared with standard 20 minute therapy was evaluated. The repair cartilage was evaluated and graded on a standard scale for the gross and histologic appearance. Ultrasound treatment significantly improved the morphologic features and histologic characteristics of the repair cartilage compared with nontreated controls. Earlier, better repair with less degenerative changes at later times was observed in defects treated with ultrasound. Doubling the treatment time to 40 minutes daily significantly increased the histologic quality of the repair cartilage. In the current animal model, daily low-intensity pulsed ultrasound had a significant positive effect on the healing of osteochondral defects.

Relationships between ball velocity and throwing mechanics in collegiate baseball pitchers

Although ball speed is considered a measure of success in baseball pitching, little is known about the relationship between ball velocity and pitching mechanics. Investigation of this relationship has been limited, and the studies carried out have varied in methodology. Three-dimensional, high-speed (240 Hz) video data were collected on fastballs from 54 collegiate baseball pitchers. Kinematic parameters related to pitching mechanics and resultant kinetics on the throwing shoulder and elbow were calculated. Multiple linear regression analysis was used to relate ball velocity and pitching mechanics. Ball velocity averaged 35 m/sec (79 mph) for the 54 college pitchers. Nearly 70% of the variability in ball speed can be explained by a combination of 10 parameters related to pitching mechanics. Body mass and 9 temporal and kinematic parameters related to pitching mechanics combine to account for 68% of the variance in ball velocity for a collegiate population of athletes. These variables can be manipulated via mechanical changes and sport-specific training to affect ball velocity. The results of the study can be used to increase ball velocity while at the same time minimizing stresses on the throwing arm elbow and shoulder. Improved training programs can begin to be developed based on these data.

Kinematics and Kinetics of Elite Windmill Softball Pitching

Background A significant number of time-loss injuries to the upper extremity in elite windmill softball pitchers has been documented. The number of outings and pitches thrown in 1 week for a softball pitcher is typically far in excess of those seen in baseball pitchers. Shoulder stress in professional baseball pitching has been reported to be high and has been linked to pitching injuries. Shoulder distraction has not been studied in an elite softball pitching population. Hypothesis The stresses on the throwing shoulder of elite windmill pitchers are similar to those found for professional baseball pitchers. Study Design Descriptive laboratory study. Methods Three-dimensional, high-speed (120 Hz) video data were collected on rise balls from 24 elite softball pitchers during the 1996 Olympic Games. Kinematic parameters related to pitching mechanics and resultant kinetics on the throwing shoulder were calculated. Multiple linear regression analysis was used to relate shoulder stress and pitching mechanics. Results Shoulder distraction stress averaged 80% of body weight for the Olympic pitchers. Sixty-nine percent of the variability in shoulder distraction can be explained by a combination of 7 parameters related to pitching mechanics. Conclusion Excessive distraction stress at the throwing shoulder is similar to that found in baseball pitchers, which suggests that windmill softball pitchers are at risk for overuse injuries. Normative information regarding upper extremity kinematics and kinetics for elite softball pitchers has been established.

Semiconstrained Primary and Revision Total Elbow Arthroplasty with Use of the Coonrad-Morrey Prosthesis

BACKGROUND Semiconstrained total elbow prostheses are used routinely by many surgeons to treat a variety of severe elbow disorders. Our objective was to review the results of primary and revision total elbow arthroplasty with use of the Coonrad-Morrey prosthesis. The selected use of this semiconstrained implant in patients with instability and poor bone stock was hypothesized to provide inferior results compared with those in the published reports. METHODS The results of sixty-seven semiconstrained total elbow arthroplasties that were performed in fifty-six patients between 1990 and 2003 were evaluated. Thirty-seven elbows had a primary arthroplasty and were followed for a mean of eighty-six months, and thirty elbows had a revision arthroplasty and were followed for a mean of sixty-eight months. Mayo elbow performance scores and radiographic analyses were used to assess the clinical results. RESULTS In the primary arthroplasty group, the average flexion improved from 116 degrees to 135 degrees; average extension, from -40 degrees to -33 degrees; average pronation, from 60 degrees to 81 degrees; and average supination, from 60 degrees to 69 degrees. The improvements in flexion and pronation were significant (p<0.001 for both). Preoperatively, twenty-five (74%) of thirty-four elbows with data available had moderate or severe pain, whereas only four (11%) had pain postoperatively. The average postoperative Mayo score (and standard deviation) was 84+/-16. Eleven of the thirty-seven primary replacements failed, and the five-year survival rate was 72%. In the revision arthroplasty group, average flexion improved from 124 degrees to 131 degrees; average extension, from -32 degrees to -22 degrees; average pronation, from 66 degrees to 75 degrees; and average supination, from 64 degrees to 76 degrees; the improvement in supination was significant (p<0.05). Preoperatively, eighteen (64%) of the twenty-eight elbows with data available had moderate or severe pain, while only five (17%) had pain postoperatively. The average postoperative Mayo score was 85+/-16. Eleven of the thirty revision replacements failed, and the five-year survival rate was 64%. CONCLUSIONS A Coonrad-Morrey semiconstrained total elbow arthroplasty provides excellent pain relief and good functional return in patients with severe destructive arthropathy. The higher prevalence of failure in this cohort compared with series reported elsewhere is likely due to adverse patient selection as this implant was reserved for more complex arthroplasties with severe bone loss and ligamentous laxity.

Posterior cruciate ligament injuries of the knee joint

Posterior cruciate ligament (PCL) injuries have a reported incidence of between 3 and 37%, depending on the clinical setting. The most common mechanism of injury in motor vehicle accidents is a dashboard injury or direct force to the proximal anterior tibia. Sports related injuries result from hyperflexion of the knee with the foot typically plantarflexed. The latter mechanism is the most common cause of isolated PCL injuries, while in the trauma population as many as 95% of patients with knee injuries have combined ligamentous damage. Improved knowledge at an anatomical, biomechanical and clinical level has provided the orthopaedist with a more defined treatment algorithm. Isolated, partial PCL injuries (grades I and II) can best be treated nonoperatively while complete injuries (grade III) may require operative treatment based on clinical symptoms. All combined ligamentous injuries usually respond best with surgical management.

Differential phenotypic characteristics of heterogeneous cell population in the rabbit periosteum

Background Periosteum and periosteum-derived progenitor cells have demonstrated the potential for stimulative applications in repair of various musculoskeletal tissues. It has been found that the periosteum contains mesenchymal progenitor cells that are capable of differentiating into either osteoblasts or chondrocytes, depending on the culture conditions. Anatomically, the periosteum is a heterogeneous multilayered membrane, consisting of an outer fibrous and an inner cambium layer. The present study was designed to elucidate the phenotypic characteristics of fibrous and cambium layer cells in vitro. Methods Using a sequential enzymatic digestion method, fibrous and cambium layer cells were harvested separately from periosteum-bone explants of the proximal tibia of 6-month-old New Zealand White rabbits. Results We found that the cells from each layer showed distinct phenotypic characteristics in a primary monolayer culture system. Specifically, the cambium cells demonstrated higher osteogenic characteristics (higher alkaline phosphatase and osteocalcin levels) than the fibrous cells. However, these differences diminished with time in vitro. Interpretation Our findings suggest that the periosteum has phenotypically distinct heterogeneous cell populations. Care must be taken in order to identify and distinguish the intrinsic phenotypes of the heterogeneous periosteum-derived cell types in vitro.

The Effect of Low-Intensity Pulsed Ultrasound on Autologous Osteochondral Plugs in a Canine Model:

Background Low-intensity pulsed ultrasound promotes the enchondral portion of fracture healing, which has a direct stimulatory effect on cartilage formation and maturation. Hypothesis Daily ultrasound treatment positively affects the repair and incorporation of modified autologous osteochondral plugs in a canine model. Study Design Controlled laboratory study. Methods In 18 dogs, 2 autologous plugs separated from host cartilage by a 1.5-mm gap were created on the medial femoral condyle in both knees of each dog. One knee was treated daily with a clinically available ultrasound bone stimulator. Animals were sacrificed after 6 and 12 weeks of therapy and the articular surfaces evaluated grossly and histologically. Results Ultrasound-treated sites had significantly improved gross appearance at 6 weeks and histologic appearance at 6 and 12 weeks. The interface repair tissue of ultrasound-treated sites had a more normal translucent appearance than control sites. Ultrasound treatment improved the cell morphologic characteristics of the interface repair tissue and increased subchondral bone regeneration. Bonding of the interface repair tissue between plug and adjacent cartilage was significantly improved compared with control sites. Conclusion Low-intensity pulsed ultrasound improved interface cartilage repair of autologous osteochondral plugs compared with controls in a canine model. Clinical Relevance Improvements in the quality and rate of repair of autologous osteochondral plugs may reduce postoperative recovery time and improve functional outcome.

Arthroscopic diagnosis and treatment of cartilage injuries

The introduction of new surgical techniques in the treatment of cartilaginous injuries has created hope for progress in the treatment of these challenging injuries. However, the results from these interventions vary according to the degree of arthritic changes within the joint, the type of postoperative rehabilitation program, and the length of follow-up. In this article, the scientific background concerning classification and repair techniques for cartilage injuries is reviewed. Also outlined are the clinical results reported to date. Anatomic location, size, depth, consistency, gross appearance, and whether the lesion is in a weight-bearing or non-weight-bearing area should be taken into account when performing an arthro-scopic diagnosis of cartilage injury. Radiographic analysis and magnetic resonance imaging will often be helpful in ruling out commonly associated joint injuries. The use of such new therapies as mosaic arthroplasty and autologous chondrocyte implantation has not been proved superior to the bone marrow-based techniques of microfracture or débridement of the lesion. Postoperative rehabilitation, including weight-bearing status and prevention of muscle atrophy, are considered just as important in achieving successful results. The long-term outcomes of operative repair of cartilaginous injuries in the prevention of joint degeneration is currently unknown and will rely on further progress in basic science and clinical orthopedic research.