Knee arthroplasty rating

Preoperative phenotype has no significant impact on the clinical outcomes and long-term survival of mechanically aligned total knee arthroplasty in Asian patients with osteoarthritis

Aims

The aim of this study was to investigate the distribution of phenotypes in Asian patients with end-stage osteoarthritis (OA) and assess whether the phenotype affected the clinical outcome and survival of mechanically aligned total knee arthroplasty (TKA). We also compared the survival of the group in which the phenotype unintentionally remained unchanged with those in which it was corrected to neutral.

Methods

The study involved 945 TKAs, which were performed in 641 patients with primary OA, between January 2000 and January 2009. These were classified into 12 phenotypes based on the combined assessment of four categories of the arithmetic hip-knee-ankle angle and three categories of actual joint line obliquity. The rates of survival were analyzed using Kaplan-Meier methods and the log-rank test. The Hospital for Special Surgery score and survival of each phenotype were compared with those of the reference phenotype with neutral alignment and a parallel joint line. We also compared long-term survival between the unchanged phenotype group and the corrected to neutral alignment-parallel joint line group in patients with Type IV-b (mild to moderate varus alignment-parallel joint line) phenotype.

Results

The most common phenotype was Type I-b (mild to moderate varus alignment-medial joint line; 27.1% (n = 256)), followed by Type IV-b (23.2%; n = 219). There was no significant difference in the clinical outcomes and long-term survival between the groups. In Type IV-b phenotypes, the neutrally corrected group showed higher 15-year survival compared with the unchanged-phenotype group (94.9% (95% confidence interval (CI) 92.0 to 97.8) vs 74.2% (95% CI 98.0 to 100); p = 0.020).

Conclusion

Constitutional varus was confirmed in more than half of these patients. Mechanically aligned TKA can achieve consistent clinical outcomes and long-term survival, regardless of the patient's phenotype. The neutrally corrected group had better long-term survival compared with the unchanged phenotype group.

[Open reduction and internal fixation with plate via posteromedial approach of retaining pes anserinus tendon in the treatment of tibial plateau fracture]

OBJECTIVE

To compare the effects of cutting and retaining the pes anserinus tendon on effectiveness following tibial plateau fracture.

METHODS

A clinical data of 40 patients with tibial plateau fracture treated with open reduction and internal fixation with plate via posteromedial approach between January 2015 and January 2020 was retrospectively analyzed, including 18 patients retained the pes anserinus tendon (study group) and 22 patients cut the pes anserinus tendon (control group) during operation. There was no significant difference in gender, age, side of affected knee, cause of injury, Schatzker classification, time from injury to operation, and associated ligament injury between the two groups ( P>0.05). The operation time, intraoperative blood loss, hospital stay, anatomic reduction rate, incidence of complications, fracture healing time, knee flexion and extension range of motion at 2 weeks and 12 months, and knee extension range of motion at 3 months after operation were recorded and compared between the two groups. The visual analogue scale (VAS) score was used to evaluate the early postoperative pain improvement at 1, 3, and 14 days after operation and hospital for special surgery (HSS) score was used to evaluate the improvement of knee function at 3, 6, and 12 months after operation.

RESULTS

The patients in both groups were followed up 12-15 months with an average of 12.8 months. There was no significant difference in operation time, intraoperative blood loss, and fracture healing time between the two groups ( P>0.05). The hospital stay in the control group was significantly longer than that in the study group ( t=8.339, P=0.000). There was no significant difference in the anatomic reduction rate (90.9% vs. 83.3%) between the control group and the study group ( χ ²=0.058, P=0.810). There were 1 case of proximal tibial osteomyelitis, 3 cases of skin necrosis, 3 cases of traumatic arthritis, and 2 cases of lower deep venous thrombosis after operation in the control group, and 1 case of metaphyseal nonunion, 2 cases of traumatic arthritis, and 1 case of lower deep venous thrombosis in the study group, showing no significant difference in the incidence of complications (40.9% vs. 22.2%) between the two groups ( χ ²=1.576, P=0.209). In the study group, knee flexion and extension range of motion at 2 weeks and 12 months and knee extension range of motion at 3 months after operation were significantly better than those of the control group ( P<0.05). VAS scores and HSS scores in both groups improved with time after operation ( P<0.05), in addition, the HSS score and VAS score of the study group were significantly better than those of the control group ( P<0.05).

CONCLUSION

Compared with traditional pes anserinus tendon cutting group, pes anserinus tendon retaining group can significantly reduce postoperative short-term pain, improve postoperative knee range of motion and knee function within 1 year after operation.

The effect of postoperative range of motion on functional activities after posterior cruciate-retaining total knee arthroplasty

BACKGROUND

Range of motion is recognized as an important indicator of the success of a total knee replacement; however, an optimal range of motion has yet to be defined. This study was designed to determine the optimal range of motion for knee function after total knee arthroplasty with a posterior cruciate-retaining prosthesis.

METHODS

We retrospectively reviewed 5556 primary total knee arthroplasties performed with posterior cruciate-retaining prostheses between 1983 and 2003. The relationship between postoperative range of motion and pain, walking ability, stair-climbing ability, and knee function scores was examined at three to five years postoperatively. The relationship between a postoperative flexion contracture or hyperextension and knee function was also examined.

RESULTS

Patients with 128 degrees to 132 degrees of motion obtained the highest scores for pain, walking, and knee function and the highest Knee Society scores. The outcomes became substantially compromised with motion of <118 degrees . Patients with 133 degrees to 150 degrees of motion had the highest scores for stair-climbing. A postoperative flexion contracture and hyperextension were associated with lower scores for pain, walking, stair-climbing, and knee function.

CONCLUSIONS

The best functional results following total knee arthroplasty are achieved with 128 degrees to 132 degrees of motion. A postoperative flexion contracture and hyperextension of >or=10 degrees are associated with a poorer outcome except that stair-climbing is improved with more motion.

Functional rating for knee arthroplasty: comparison of three scoring systems

This study evaluated the reliability of three rating systems for total knee arthroplasty. Twenty-nine patients were assessed by six observers with the American Knee Society Score, the British Orthopaedic Association Score, and the Oxford 12-item questionnaire. The inter- and intraobserver variations were calculated for the American Knee Society Score and the British Orthopaedic Association Score, as was the reproducibility of the Oxford 12-item questionnaire. Components of the scores were evaluated for agreement using Kappa statistics. The British Orthopaedic Association Score had smaller interobserver variation compared to the American Knee Society Score, and the greatest reproducibility of the three systems. This was attributed to the equal weighting of its component variables. The Oxford 12-item questionnaire, a self-administered questionnaire that eliminates interobserver error, emerged as the most reliable system. Observer experience affected the reliability of the American Knee Society Score and the British Orthopaedic Association Score. Subjective variables were more reliable and reproducible than the objective components.

The history of the STAR total ankle arthroplasty

The STAR ankle replacement prosthesis has almost a 30-year history. The current FDA study of the device in the United States is very encouraging. The prosthesis does show great promise but needs further study. Further elucidation of the postoperative radiographs and the various areas of lucency and their significance should be studied. The learning curve for implantation is very steep.

Surgical repair of cartilage defects of the patella

The structure and biomechanical forces on the patellar joint challenges researchers to define an ideal method for resurfacing the patellar cartilage. The articular surface of the patella presents variability between individuals, and has various minor articulations that bear partial or total compressive, shear, and combined forces during movement. Surgical techniques for the repair of patellar cartilage defects have evolved from cumulative advances in basic science and technology. Such surgeries include the techniques that promote either fibrocartilage formation or hyalinelike cartilage formation. Techniques promoting the formation of fibrocartilage yield short-term solutions because fibrocartilage lacks the durability and the mechanical properties of articular hyaline cartilage. Currently, there is no ideal method for the repair of patellar cartilage defects; all methods are considered experimental. Additional controlled and randomized clinical studies with large series of patients and long-term followup are required.

Patient's memory or repeated pain and function scores as index for major clinical change caused by knee replacement?

Change of the clinical condition is the aim of replacement of the knee. This has at least four components: a clinical phenomenon, an event for the phenomenon, size of the event and time for the event. This study dealt with major change of pain and function at the time of remission. The agreement between the patients's opinion of change and a clinical change score was poor. That a special index of changes is needed is shown in this study.