THE TRANSLOCATION OF 32 P IN TWO SUBMERGED AQUATIC ANGIOSPERM SPECIES.

The translocation of phosphorus as 32 P was investigated in two species of rooted, submerged, aquatic angiosperm, Potamogeton pectinatus and Potamogeton crispus. Experiments were conducted in two forms of partition apparatus for periods of either 1 to 48 h or 6 to 10 days. The apparatus used for the shorter-term experiments incorporated three compartments so that possible isotope leakage through seals could be critically distinguished from plant excretion. Results of autoradiography and of radioactive counting provide evidence for a circulation of 32 P in these plants akin to that described for terrestrial plants but with slower rates of movement. Quantitative differences in rates and amounts of 2 P transport in the two species are discussed in relation to their anatomy and ecological distribution. There was no evidence of excretion of isotope, following transport, in the experiments conducted.

Joint débridement--a complement to high tibial osteotomy in the treatment of degenerative arthritis of the knee.

The management of unicompartmental osteoarthritis of the knee by high tibial osteotomy is enhanced by an associated joint débridement. A review of 120 patients who underwent the combined procedure, with follow-up to thirteen years, indicated that good or satisfactory results may be achieved in 82 per cent and that such results may be maintained over a prolonged period of review. This paper summarizes a long-term review of a series of one of us (D. L. M.), who since 1961 has practiced the combined procedure of tibial osteotomy and open joint débridement. The patient group was reviewed by him one year following surgery and then independently by the second author (R. P. W) in 1974, when 105 of the original 120 patients were available for detailed follow-up. Controversy surrounds the role of débridement when associated with osteotomy. This paper discusses both the rationale for and the results of combining these procedures. The over-all results confirm that these procedures are indeed complementary.

Shoulder impingement syndromes in athletes and their surgical management.

The painful arc syndrome may be produced by impingement of the supraspinatus tendon, the biceps tendon, or the greater tuberosity of the humerus against the coracoacromial arch. Where conservative measures have failed, surgical intervention may provide considerable symptomatic relief by decompressing the coracoacromial arch. In 20 cases surgically treated for biceps or supraspinatus impingements, 17 patients have returned to sporting activities without symptoms. The painful arc syndrome persists in three patients but they are symptomatically improved. Six patients with complete rotator cuff tears and subsequent impingement of the greater tuberosity of the humerus against the coracoacromial arch underwent widespread decompression. Five of the patients have returned to sporting activities much improved. Failure to recognize the associated acromioclavicular joint pathology is a frequent cause of failure of surgical treatment.

The results of revision of total hip arthroplasty.

The results of 140 total hip revision procedures for "non-septic" loosening, dislocation, and fracture of the femoral stem or shaft have been personally reviewed and rated by the Harris method. The minimum follow-up period was six months: thirty-three (24 per cent) showed excellent or good results, seventy-two (51 per cent) showed fair or poor results. Subsequent excision arthroplasty was performed in thirty-one patients. The infection rate for these revision procedures was very high, suggesting that many were already infected at the time of revision, and that every "loose" hip must be assumed to be infected until proved otherwise. The mortality rate of 3 per cent was surprisingly low after more than one major surgical procedure in these elderly patients.

Patellofemoral arthralgia, overuse syndromes of the knee, and chondromalacia patella.

Patellofemoral arthralgia is a very common syndrome affecting athletes. Most often, examination fails to define true pathology. Conservative treatment, an active exercise program, and sports may be undertaken without harm to the knee. The patellofemoral arthralgia syndrome must be differentiated from true chondromalacia patella, where there is actual degeneration of the patella's articular cartilage, and from other sources of internal derangement such as meniscal disease or osteochondral lesions. Careful attention to the history of onset, and provoking activities such as climbing stairs, kneeling, and crouching, will allow the physician to recognize patellofemoral arthralgia. Other common overuse syndromes also should be looked for, and differentiated from problems due to true internal derangement.

Potential complications of total knee replacement following tibial osteotomy.

Ligament balancing in total knee replacement allows the correction of virtually any intra-articular deformity and the use of a semi-constrained knee. The capacity for overcorrection to balance extra-articular deformities is, however, quite limited. The authors found this to be true in a case requiring tibial osteotomy after total knee replacement. Eventually, the patient required a long-stem hinge prosthesis. After this case, the authors have preferred to correct extra-articular bony deformities of more than 15 degrees prior to total knee replacement.

Postoperative flexion contracture of the knee: a simple technique for its treatment.

Flexion contracture is not a common problem following knee surgery, but it can be severe enough to jeopardize the success of the operation. With the Beath technique a stove-pipe cast is windowed anteriorly and the cast is padded behind the leg, which is then gently wedged into extension. In this way many flexion contractures can be gently and easily overcome. In addition, the need for serial casting or forcible manipulation is obviated and the overall rehabilitation program is unimpeded. In this paper the authors report two illustrative cases, and discuss the advantages and applications of the Beath technique.

Swan neck deformity in rheumatoid arthritis of the hand.

Swan neck deformity is not a single entity. Significantly different types of swan neck deformity are found, each demanding careful clinical evaluation and specialised treatment. This paper discusses the pathomechanics of swan neck deformity and presents a classification upon which rational treatment can be based. The surgical treatment of each variant is briefly outlined.

Treating the rheumatoid hand.

Deformities in the rheumatoid hand will vary according to whether the joints or the tendons are involved. Frequently both will be involved and several different deformities will be present in the same hand. However, a logical approach to examination and treatment, as outlined in this article, will simplify decision making and ensure prompt, appropriate treatment.

Fracture of the femoral component in unicompartmental total knee arthroplasty.

A fracture of the anterior flange of a femoral component in a unicompartmental knee has been seen. This was thought to be due to lack of bony support leading to cantilever bend. The solution would seem to be to add a metal web to strengthen that area of the femoral component.

Spontaneous rupture of the quadriceps tendon and patellar ligament during treatment for chronic renal failure.

The quadriceps tendon and patellar ligament rupture rarely, even when under great stress or trauma, but can rupture spontaneously in patients with chronic diseases such as gout, rheumatoid arthritis and renal disease. Several factors probably combine to weaken the tendon, including an impoverished local vascular supply, repeated microtrauma and secondary hypoparathyroidism with osteodystrophy. In the three cases reported here, one of which was bilateral, the patients were being treated for chronic renal disease; surgical repair of the tendons led to sound healing and a return to normal function of the joints.

Fat embolism: a rational approach to treatment.

Fat embolism following major trauma may be associated with a clinical syndrome with widespread pulmonary and systemic manifestations, the most serious being profound hypoxia with secondary atelectasis, pulmonary edema and pulmonary hypertension, and cerebral depression. Though the origin of the embolic fat is debated, there is evidence to support its origin from both the bone marrow and intravascular chylomicron coalescence.The clinical manifestations are largely explained by a prime assault upon the lung parenchyma and alteration in platelet characteristics.Early recognition and treatment of the condition is essential, adequate oxygenation being of prime importance. Steroids and heparin have been found to be of benefit.

Dislocation requiring revision in total hip arthroplasty.

In a study of 141 hip revisions seventeen were found to be due to recurrent dislocation. Thirteen cases occurred immediately postoperatively and four more than two years following surgery. In the early cases component malposition was found to be the commonest cause of dislocation. Revision resulted in only 40% acceptable results.

"Bursal reactions" in rotator cuff tearing, the impingement syndrome, and calcifying tendinitis.

Subacromial bursal specimens from 63 patients undergoing surgery for rotator cuff tearing (n = 43), the impingement syndrome (n = 14), and calcifying tendinitis n = 6) were studied to characterize the reactions that develop at the tendinopathy "lesional" sites. Intensity of the bursal reactions and production of type III collagen vary considerably, with the highest incidence of both seen in patients with rotator cuff tears. The intensity of bursal reactions correlated with the degree of formation of perivascular new collagen and type III collagen expression. In 22 of the 63 patients the bursal reaction distant to the tendon lesion was also studied. It was minimal and did not correlate to the lesional bursal findings. A strong correlation, however, existed between surgical appearance and histologic grading. The term "localized bursal reaction" as opposed to bursitis more correctly describes bursal involvement. Resection of bursal tissues should be limited to the lesional tissue that interferes with subacromial motion.

Unicompartmental knee replacement.

The results of unicompartmental knee replacement in a series of 83 knees were reviewed for the period of 1970 to 1978; 30.1 percent achieved good or excellent results; 48.2 percent fair or poor results; 21.7 percent were failures. The vast majority of failures and poor results were due to technical errors. Only 9.6 percent of the nonoperated contralateral compartments required further surgery.

Revision of total knee replacement.

In the London and Toronto areas between 1969 and 1978, 597 patients had 661 cemented knee replacements. Eighty-nine (13.5%) prostheses failed; 73 of them were revised. Nineteen (2.9%) failed primarily because of infection. The revised replacements were examined and rated using a modification of the British rating system. The overall results of revision were excellent or good in 30% and fair or poor in 52%. Fusion was attempted in two patients after revision. In 16 patients with failed replacements that were not revised, fusion was attempted in 9; 4 of the 16 patients had amputation. The results of failure in knee replacement surgery are similar to those of hip replacement, but are helped considerably by lower patient expectation.

Radiographic and morphologic studies of load-bearing porous-surfaced structured implants.

Load-bearing porous-surfaced implants in dogs which failed were not incorporated by bone ingrowth. The implants were incorporated only by fibrous tissue ingrowth. Collagen fiber orientation within this fibrous tissue and Sharpey's fiber-like features at the interface between the fibrous tissue and a surrounding layer of dense bone suggest the adequacy of the fibrous tissue attachment for support of a loaded implant. The surrounding dense bone layer could be distinguished radiographically within three months of the operation. This radiopaque line is similar to that observed around some porous surfaced hip implants in humans. Observations of animal mobility up to six months postoperatively suggest that fibrous connective tissue growth into porous implants can provide adequate mechanical support for weight-bearing dogs.