James G. Howe

A comparison of radiographic findings in fusion and nonfusion patients ten or more years following lumbar disc surgery.

Ninety-six patients who had undergone disc excision and midline spinal fusion and 36 patients who had had simple disc excision had spinal radiographs made 10 or more years postoperatively. Claw spurs were found most commonly at the L2-3 and L3-4 levels in fusion patients, particularly male laborers. Traction spurs with segmental hypermobility were found more commonly at the L4-5 level in patients whose spines were not fused, particularly women. Total lumbar flexion-extension was greater in nonfusion than in fusion patients, but the L1 - 3 mobility was greater in those who had undergone fusion, suggesting a compensatory increase in the range of lumbar motion. Segmental mobility at levels of surgery in nonfusion patients was similar in those with good and those with poor clinical results. Disc space narrowing was common at levels of operation, but did not correspond to the clinical result. Pseudarthrosis was demonstrated in 26% of fusion patients, but was of no clinical significance. Although complex radiographic changes follow lumbar disc surgery, with or without failure, it is concluded that the plane radiograph is of little aid in determining the source of postoperative pain. The sole exception is that of acquired spondylolysis, which was found in 2.5% of this group of fusion patients, and was clearly associated with a poor clinical outcome. Symptomatic degenerative disc disease at levels above lumbar spinal fusions appears to be an uncommon clinical problem.

Anterior cruciate ligament reconstruction using quadriceps patellar tendon graft Part I. Long-term followup

Eighty-three patients with ACL reconstructions using the quadriceps patellar tendon graft were evaluated in a 10 year (mean, 5.5 years) follow-up study. A five-part analysis, consisting of physical examination, question naire, Genucom analysis, operative note review, and radiographs, was performed. Seventy-six percent were categorized as satisfactory. Ninety-two percent were content with their results, while only 4% were unsatis fied. Ninety-three percent of the patients had no signif icant pain and 95% had no giving way postreconstruc tion. Ninety-two percent had no more than a mild functional deficit. Eighty-seven percent and 90% of the patients had no significant Lachman or pivot shift by examination, respectively. Our results showed no in crease in failure over time (1 to 10 years), although those operated on during the initial 5 years showed more radiographic degenerative changes. Plotting our results in classification systems of other authors yielded success rates as good as or better than those using our own criteria. An objective means by which to quan tify laxity did not reliably correlate with the quantifying of laxity made by physical examination. Only the lack of a formal rehabilitation program greater than 4 months postoperatively and repaired tears of the medial or lateral collateral ligaments proved to be significant risk factors for poor recovery.

Disc Excision and Spine Fusion in the Management of Lumbar Disc Disease: A Minimum Ten-Year Followup

Seventy-nine percent of 312 patients who underwent lumbar disc surgery were evaluated at least 10 years postoperatively (mean=13.7 years). Residual back and nerve root symptoms and functional impairment were equally as common among the 143 patients who underwent fusion as they were among the 64 patients who did not. Thirty percent of the patients whose spines were fused and 37.7% of those patients whose spines were not fused were considered longterm failures because of persistent symptoms or the need for reoperation. Thirty-seven percent of the fusion patients had persistent graft donor site symptoms. Examined patients showed a high percentage of residual neurologic defects. An unexplained positive Trendelenburg sign was present in 14.8% of the fusion patients and in 18.2% of the patients whose spines were not fused. Although retrospective studies often have problems of accuracy, this analysis confirms other observations that midline spinal fusion offers few benefits in the management of lumbar disc disease.

The effect of functional knee-braces on strain on the anterior cruciate ligament in vivo

Functional knee-braces are widely used to protect injured or reconstructed anterior cruciate ligaments, despite the fact that few scientific data support their efficacy. We studied seven functional braces, representative of both the typical custom-fit and off-the-shelf designs. The braces were tested on subjects who had a normal anterior cruciate ligament and were scheduled for arthroscopic meniscectomy or exploration of the knee under local anesthesia. After the operative procedure, a Hall-effect strain-transducer was applied to the anterior cruciate ligament. Under low anterior shear loads, two braces provided some protective strain-shielding effect compared with no brace, but this strain-shielding effect did not occur at the higher anterior shear loads expected during the high-stress activities common to athletic events. The DonJoy, Townsend, C.Ti., and Lenox Hill braces demonstrated a strain-shielding effect on the anterior cruciate ligament with an internal torque of five newton-meters applied to the tibia. None of the braces had any effect on strain on the anterior cruciate ligament during active range of motion of the knee from 10 to 120 degrees or during isometric contraction of the quadriceps. Wearing of a brace did not produce an increase in the value for strain on the anterior cruciate ligament. For the activities that were evaluated in this study, none of the braces produced adverse effects on the anterior cruciate ligament, and there were no significant differences in the strain on the anterior cruciate ligament between the use of a custom-fit or an off-the-shelf brace design. There were no apparent advantages of the more expensive custom-made braces compared with the off-the-shelf designs.

The effects of questionnaire design on the determination of end results in lumbar spinal surgery

Two hundred and seven patients followed a minimum of 10 years after a single lumbar disc operation were evaluated using 14 different questionnaires that measure surgical outcomes. Dependent on the questionnaire design, the satisfactory outcomes for this population ranged from 97% to 60%, which is statistically significant. The authors conclude that the reported outcomes for lumbar spinal surgery are significantly manipulated by the criteria selected for the assessment of end results.

Failed Lumbar Disc Surgery Requiring Second Operation: A Long-term Follow-up Study

Forty-five patients who had lumbar disc surgery 10 or more years previously, and had required a second operative procedure, have been evaluated. Failures occurred up to 16 years after the first operation, and were most commonly due to pseudoarthrosis in the patients who underwent spinal fusion initially, and to recurrent disc lesions at the same level as previous surgery in the patients who did not have fusion. The clinical and functional results in the second group of patients who required a second procedure were comparable to those of patients who required only a single procedure. In contrast, patients who had undergone spinal fusion who required a second procedure had significantly worse clinical and functional results, both in comparison to the patients who did not undergo fusion as well as to patients who had had fusion as a single procedure. The only predictable, demonstrable source of failure was acquired spondylolysis. Frequently, repair of pseudoarthrosis did not lead to symptomatic relief. These data suggest that spinal fusion, when it fails, has a significantly worse prognosis than simple disc excision in the management of lumbar disc disease.

Arthroscopic strain gauge measurement of the normal anterior cruciate ligament

This article describes a new arthroscopic technique to study the anterior cruciate ligament (ACL) in vivo. A Hall effect strain transducer (HEST) is inserted arthroscopically into the anterior medial band (AMB) of the ACL. The strain is calculated from HEST displacement data. This method determines a reference length of the AMB when it becomes taut and load bearing. Data from HEST implantation in five patients with normal ACLs are reported. The HEST was implanted in the AMB with patients under local anesthesia. Strain was calculated during anterior-posterior shear testing and isometric quadriceps contractions at 30 and 90 degrees of knee flexion. The results demonstrate that this technique is safe and reliable. Lachman testing (anterior shear testing at 30 degrees) caused significantly higher strain in comparison to the drawer tests (anterior shear testing at 90 degrees). A significant increase in strain occurred during isometric quadriceps contraction when the knee was flexed at 30 degrees. No significant change in strain was measured, however, during isometric quadriceps contraction at 90 degrees of flexion. These results confirm previous studies showing that the Lachman test is a more sensitive clinical method for evaluating the AMB. They suggest that isometric quadriceps activity at 90 degrees of knee flexion can be prescribed for rehabilitation without risk of increased strain of the AMB.

Anterior cruciate ligament reconstruction using quadriceps patellar tendon graft Part II. A specific sport review

Eighty-three patients, from a 10 year follow-up study, who underwent ACL reconstruction with a quadriceps patellar tendon graft were reviewed. A questionnaire qualifying their sports performance in 20 possible sports compared their preinjury status to postinjury and postreconstructive surgery. Successful and unsuccess ful patients, as determined by our previous investiga tion, were likewise compared. Sports performance, regardless of the sport or level of competition, decreased substantially postinjury and then rose significantly to near but not equal to patient preinjury status. The most strenuous sports dipped to the lowest performance level after injury and returned with a correspondingly more modest gain after the reconstruction. Not surprisingly, successful patients had a more impressive return in performance than unsuccessful patients, mirroring their clinical grading. Of those deemed unsatisfactory (N = 20), graft failures were no worse off in performance rating than those that were classified as unsatisfactory because of per sistent symptoms.

The long-term effects of spinal fusion on the sacroiliac joints and ilium.

Ninety-six patients who had lumbar disk excision and primary posterior fusion were studied 10 or more years after their operations. Thirty-seven per cent complained of persistent graft donor site pain. A comparison of fused patients with and without donor site pain and 36 patients who underwent simple disk excision, revealed no differences in the flexion-extension mobility of the sacroiliac joints, or degenerative changes in the sacroiliac joints. Ectopic bone formation at graft donor sites, and cluneal nerve neuromata did not influence the result. Patients with graft donor site pain had significantly greater complaints of persistent low back pain, postoperative leg pain, and lost more time from work. If the graft was taken from the same side as that of preoperative leg pain, persistent complaints were more common. It is concluded that the sacroiliac joints are not adversely affected by lumbar spine fusion, and that persistent donor site pain is more likely part of a total pain complex referred from the lumbar spine. The sacroiliac joints appear to be relatively noncontributory to problems following lumbar disk surgery.

Longitudinal crack propagation in bone around femoral prosthesis

Intraoperative femoral fracture is a well-recognized technical complication of cementless total hip arthroplasty. This study was designed to establish an in vitro model for initiation and propagation of fractures of the proximal femur in cementless THA and to assess the effect of fracture fixation in the form of cerclage wiring and drilling a hole in the distal extent of the fracture line. Fourteen human anatomic femur specimens were studied. Longitudinal cracks were made and propagation was performed on a materials testing system machine. A drill hole at the tip of a longitudinal crack does not prevent crack propagation. However, cerclage wiring has a statistically significant effect (p less than 0.025) on the ability of the fractured femur to withstand increased load.