Hugh S. Tullos

The anatomic basis of femoral component design.

The shape of the femoral canal is variable, much more variable, in fact, than most contemporary designs of femoral components would suggest or can accommodate. In the face of this variability, line-to-line or surface-to-surface contact is not expected between cementless implants and much of the endosteal surface. It also is apparent that changes in implant design are still needed if the normal biomechanics of the hip joint are to be restored in each patient and if component fixation is to be optimized. Most cementless components aim to achieve proximal load transfer to the femoral canal. However, increasing clinical evidence suggests that distal filling of the femur also is necessary to minimize the incidence of postoperative symptoms, particularly in revision procedures. If this is indeed the case, more accommodating designs of femoral components are needed that will enable proximal and distal fitting at the femoral canal so that stable fixation may be achieved regardless of variations in bone geometry.

Simple dislocation of the elbow in the adult. Results after closed treatment.

The long-term results after treatment of simple dislocation of the elbow in fifty-two adults were evaluated with regard to limitation of motion, pain, instability, and residual neurovascular deficit. All patients were treated with traditional closed reduction, but the duration of immobilization before commencement of active motion varied. Goniometric, photographic, and radiographic data were compiled for these patients, who had an average follow-up of 34.4 months. Despite the generally favorable prognosis for this injury, 60 per cent of the patients reported some symptoms on follow-up. A flexion contracture of more than 30 degrees was documented in 15 per cent of the patients; residual pain, in 45 per cent; and pain on valgus stress, in 35 per cent. Prolonged immobilization after injury was strongly associated with an unsatisfactory result. The longer the immobilization had been, the larger the flexion contracture (p less than 0.001) and the more severe the symptoms of pain were. The results indicate that early active motion is the key factor in rehabilitation of the elbow after a dislocation.

The Effect of Femoral Component Position on Patellar Tracking After Total Knee Arthroplasty

In a laboratory study, seven fresh anatomic knee specimens were evaluated to define the three-dimensional motions of the patella before and after total knee arthroplasty (TKA) with the AMK knee. The patella was displaced medially by an average of 4 mm and tilted medially by an average of 4 degrees after standard TKA. Medial translation or internal rotation of the femoral component further displaced and tilted the patella medially, but lateral translation or external rotation of the femoral component produced less predictable changes in patellar tracking. The patterns of patellar tracking after external rotation of the femoral component came closer to reproducing those of the intact knee than any other femoral component position. The high lateral ridge on the femoral component effectively prevents patellar dislocation but may produce abnormally high stresses on the patellar implant, especially if the implant is medially displaced or internally rotated. This could lead to accelerated wear or loosening of the patellar component.

The Effect of Femoral Component Head Size on Posterior Dislocation of the Artificial Hip Joint

Background: Posterior dislocation continues to be a relatively common complication following total hip arthroplasty. In addition to technical and patient-associated factors, prosthetic features have also been shown to influence stability of the artificial hip joint. In this study, a dynamic model of the artificial hip joint was used to examine the influence of the size of the head of the femoral component on the range of motion prior to impingement and posterior dislocation following total hip replacement. Methods: Six fresh cadaveric specimens were dissected, and an uncemented total hip prosthesis was implanted in each. Each specimen was mounted in a mechanical testing machine and loaded with use of a system of seven cables attached to the femur and pelvis that simulated the action of the major muscle groups crossing the hip joint. The hip was taken through a range of motion similar to that experienced when rising from a seated position. The three-dimensional position of the femur at the points of impingement and dislocation was recorded electronically. The range of joint motion was tested with prosthetic femoral heads of four different diameters (twenty-two, twenty-six, twenty-eight, and thirty-two millimeters). Results: Significant associations were noted between the femoral head size and the degree of flexion at dislocation in ten (p = 0.001), twenty (p < 0.001), and thirty (p = 0.003) degrees of adduction. Increasing the femoral head size from twenty-two to twenty-eight millimeters increased the range of flexion by an average of 5.6 degrees prior to impingement and by an average of 7.6 degrees prior to posterior dislocation; however, increasing the head size from twenty-eight to thirty-two millimeters did not lead to more significant improvement in the range of joint motion. The site of impingement prior to dislocation varied with the size of the femoral head. With a twenty-two-millimeter head, impingement occurred between the neck of the femoral prosthesis and the acetabular liner, whereas with a thirty-two-millimeter head, impingement most frequently occurred between the osseous femur and the pelvis. Conclusions: With the particular prosthesis that was tested, increasing the diameter of the femoral head component increased the range of motion prior to impingement and dislocation, decreased the prevalence of prosthetic impingement, and increased the prevalence of osseous impingement. Clinical Relevance: These results suggest that femoral heads with a twenty-eight-millimeter diameter increase the range of motion after total hip replacement. This may be beneficial when additional factors compromising joint stability are encountered.

An analysis of 100 symptomatic baseball players

The management of baseball elbow injuries, both operative and nonoperative, was usually successful, permitting continued high-level athletic participation. Surgery was particularly effective in those cases with loose bodies. In the shoulder, symptoms occurred in the anterior and posterior regions. Each area presented difficulties in accurate diagnosis. The management of anterior symptoms was primarily nonoperative, surgery being reserved as a salvage procedure. In the posterior capsular syndrome, the source of pain is still unclear.

Contributory factors and etiology of sciatic nerve palsy in total hip arthroplasty

Twenty-three peroneal and sciatic nerve palsies occurred in 21 patients following hip arthroplasty. Apparent risk factors included revision operations, being female, and significant lengthening of the extremity. The amount of lengthening was correlated with the development of either a peroneal palsy or sciatic nerve palsy. In cases of peroneal palsy the average lengthening was 2.7 cm (1.9 cm-3.7 cm) in comparison with 4.4 cm (4.0 cm-5.1 cm) for sciatic nerve palsies. Seven of these nerve palsies occurred among 614 consecutive patients treated at one institution during the period 1983-1985. This corresponded to an overall incidence of 1.1%. Electromyography demonstrated that peroneal stretch palsies originated primarily at the level of the neck of the fibula with some diffuse but lesser involvement along the proximal course of the peroneal division of the sciatic nerve.

Arthroscopic subacromial decompression An anatomical study

Anterior acromioplasty as described by Neer has been an effective procedure for shoulder impingement syn drome. Recent presentations by Ellman suggest that an effective acromioplasty may be performed arthros copically. These clinical reports have not been sup ported by any laboratory experience. The purpose of our study was to examine the feasibility and attempt to quantitate the results of arthroscopic subacromial de compressions. Six acromioplasties were performed according to the recommended technique of Dr. Neer to create a stand ard for comparison. Fourteen fresh postmortem speci mens were studied. In seven shoulders a standard acromioplasty was performed with an osteotome. In seven shoulders an acromioplasty was performed using standard arthroscopic approaches and motorized in struments. In five shoulders an isolated division of the coracoacromial ligament was performed arthroscopi cally. The coracoacromial ligament was completely di vided in all five cases. In the osteotome group adequate bone was resected in 75% (21/28) measured locations. In the arthroscopic group adequate bone was removed at 86% (24/28) location. This difference is not statisti cally significant. In the cadaver, anterior acromioplasty was performed effectively and predictably with arthroscopic instru ments. This compared favorably to a conventional os teotome acromioplasty. It was concluded that coraco acromial ligament division can be accomplished.

Little League survey: the Houston study

1. In a study of 595 Little League pitchers, approximately 17% had a history of elbow symptoms: only 1% had elbow symptoms which had ever excluded them from pitching. There was no correlation between the presence of symptoms and years of pitching experience. 2. Some limitation of active extension of the elbow was seen in 12% of the pitchers; however, there was no correlation between elbow flexion contractures and years of pitching experience, symptoms, or roentgenographic pathology. No normal child had an elbow flexion contracture greater than 15 degrees. 3. A slight valgus carrying angle is considered a normal anatomic variant in the dominant arm. There was no correlation between valgus carrying angle and years of pitching experience or symptoms or roentgenographic pathology. 4. No roentgenographic evidence of avascular necrosis of the capitellum, radial head, or both was seen in this population. 5. Roentgenographic findings such as bony hypertrophy, enlargement of the medial epicondyle, and secondary ossification centers are normal anatomic variants not related to symptoms. Undisplaced stress fractures of the medial epicondyle respond well to conservative treatment, with no functional residual.

Use of a hinged silicone prosthesis for replacement arthroplasty of the first metatarsophalangeal joint.

A series of ninety consecutive total joint replacements of the first metatarsophalangeal joint with a flexible hinged prosthesis was reviewed after an average duration of follow-up of three years (range, twenty-four to sixty-one months). Although subjectively the results were satisfactory in most of the patients, and pain, the most common preoperative symptom, was reduced, mechanical failure of the implant was common, as determined radiographically. The frequency of failure of the implant and the extent to which it failed were related to the length of time that the implant had been in place. The range of motion of the metatarsophalangeal joint was decreased from normal. Dorsiflexion averaged 26 degrees and plantar flexion, 18 degrees. Callosities under at least one metatarsophalangeal joint were noted in fifty (69 per cent) of the feet that had a physical examination. Pedobarographic analysis of the distribution of plantar pressure revealed that none of the patients exerted weight-bearing pressures on the affected great toe. However, the subjective results were not significantly associated with radiographic evidence of failure of the implant. Despite its success in relieving the symptoms in our patients, we have abandoned this procedure because of the high and increasing rate of failure of the implant, as demonstrated radiographically.

The effect of continuous epidural analgesia on postoperative pain, rehabilitation, and duration of hospitalization in total knee arthroplasty.

Efficacies of three alternate methods of postoperative analgesia were studied in 156 patients who had total knee arthroplasty (TKA). Forty-two of these patients received parenteral meperidine hydrochloride or morphine (Group 1), 58 patients received periodic epidural injections of morphine (Group 2), and 56 patients received continuous epidural infusions of bupivacaine hydrochloride and Duramorph (Group 3). The postoperative course of all patients was documented in terms of the incidence and severity of pain, range of joint motion, duration of hospitalization, and occurrence of complications. Although epidural analgesia increased the cost and duration of the operation, good-to-excellent pain relief was attained in 86% (Group 2) and 88% (Group 3) of cases with epidural analgesia compared with 61% of patients (Group 1) receiving conventional analgesia. Moreover, 67% of patients in Group 1 experienced frequent episodes of moderate-to-severe postoperative pain in contrast to 40% of patients in Group 2 and only 10% of patients in Group 3. As a result of diminished pain, greater joint motion was obtained within the first 72 hours in Groups 2 and 3. They also had shorter hospitalization (9.6 days versus 11.2 days for Group 1 and 10.8 days for Group 2). However, the use of epidural analgesia did not reduce the incidence of complications, including nausea. Continuous infusion of epidural bupivacaine and Duramorph provided good-to-excellent control of postoperative pain after TKA. However, better analgesics are needed to reduce the high incidence of side effects associated with various treatment methods.