Objective To summarize the current research progress about influence of patellofemoral osteoarthritis on clinical outcome of unicompartmental knee arthroplasty (UKA). Methods The recent related literature was extensively reviewed and summarized, including pros and cons to regard the patellofemoral osteoarthritis as the contraindication. Results Previous studies regarded patellofemoral osteoarthritis as the contraindication of UKA. Most of current researches show that the damage to the articular cartilage of the patellofemoral joint to the extent of full-thickness cartilage loss has no influence on outcome of UKA. There is no correlation between preoperative anterior knee pain or medial patellofemoral joint degeneration and the clinical outcome. However, lateral subluxation of the patella has an adverse impact on postoperative curative effect. Degeneration of the lateral patellofemoral joint may be a risk factor of the outcome. Conclusion Patellofemoral osteoarthritis should not be the absolute contraindication of UKA. The effect of degeneration of the lateral patellofemoral joint is not clear at present, and still needs further studies in the future.
ObjectiveTo explore the short- and mid-term effectivenesses of combined unicompartmental knee arthroplasty (UKA) and anterior cruciate ligament (ACL) reconstruction for osteoarthritis (OA) and ACL injury.
MethodsBetween January 2006 and January 2014, 32 patients with knee OA and ACL injury were treated by combined UKA and ACL reconstruction. There were 12 males and 20 females, aged 41-63 years (mean, 50 years); 17 left knees and 15 right knees were involved. The causes of ACL injury were sports injury (25 cases) and traffic accident injury (7 cases), including 27 cases of old injury and 5 cases of acute injury. Pain of the medial compartment of the knee and unstable knee joint were the main clinical symptoms. Preoperative X-ray films showed (3.1±0.6)° of varus deformity.
ResultsAll incisions healed by first intention, without complication. The patients were followed up 16-112 months (mean, 55 months). Mobile bearing dislocation occurred in 2 cases after operation, and was cured after replacing much thicker mobile bearings. X-ray films showed (4.0±0.7)° of valgus at last follow-up. There was no loosening of the prosthesis. Physiological radiolucent line (<1 mm) was observed around the tibial component in 10 patients. The Oxford Knee Score (OKS), Knee Society Score (KSS) clinical score, KSS functional score, and Tegner activity score at last follow-up were improved significantly (P<0.05). The range of motion (ROM) of the operated knee was (123.5±2.8)°, and the posterior slope of the tibial component was (3.9±1.2)° at last follow-up; a significant correlation was found between ROM and posterior slope according to the Pearson's correlation (r=0.392, P=0.031).
ConclusionCombined UKA and ACL reconstruction has good short- and mid-term effectivenesses for OA and ACL injury.
ObjectiveTo compare the effectiveness of unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) in the treatment of severe medial compartment osteoarthritis (OA).MethodsA clinical data of 69 patients (69 knees), who underwent joint replacement due to severe medial compartment OA between February 2015 and September 2018 and met the selection criteria, was retrospectively analyzed. Among them, 38 cases were treated with UKA (UKA group) and 31 cases with TKA (TKA group). There was no significant difference in gender, age, body mass index, course of disease, lesion side, and preoperative visual analogue scale (VAS) score, Hospital for Special Surgery (HSS) score, Western Ontario and McMaster University Osteoarthritis Index (WOMAC) score, Feller score, range of motion of knee, physiological and psychological scores of short-form 12 health survey scale (SF-12) between the two groups (P>0.05). The femorotibial angle (FTA) of TKA group was bigger than that of UKA group, and hip-knee-ankle angle (HKA) was smaller, showing significant differences (P<0.05). The operative time, incision length, blood loss, time for flexion 90°, ambulation time, hospital stay, and incidence of deep venous thrombosis of lower extremity were recorded and compared between the two groups. The VAS score, HSS score, WOMAC score, Feller score, range of motion, and physiological and psychological scores of SF-12 were used to evaluate patients’ quality of life. FTA, HKA, and prosthesis looseness were observed by X-ray films. Kaplan-Merier survival analysis was used to evaluate the survival rate of prosthesis.ResultsAll operations were successfully completed in both groups. Compared with TKA group, UKA group had shorter incision length, longer operative time, and less blood loss (P<0.05). There was no significant difference in time for flexion 90°, ambulation time, hospital stay, and the incidence of deep venous thrombosis of lower extremity between the two groups (P>0.05). The incisions in both groups healed by first intention. During follow-up, 3 patients in the UKA group and 1 patient in the TKA group developed mild anterior knee pain. Patients were followed up (30.7±9.6) months in the UKA group and (34.9±8.7) months in the TKA group, and the difference was not significant (t=–1.832, P=0.071). At last follow-up, there were significant differences in the HSS score, Feller score, WOMAC score, range of motion, VAS score, and physiological and psychological scores of SF-12 between pre- and post-operation (P<0.05). The range of motion in the UKA group was bigger than that in the TKA group (Z=–2.666, P=0.008), and there was no significant difference in the other indexes between the two groups (P>0.05). X-ray films showed that the alignment of the two groups recovered well, and the FTA and HKA of the two groups were improved at 1 week after operation (P<0.05). No radiolucency was found around the prosthesis during follow-up, no prosthesis loosening and meniscal bearing dislocation occurred. The survival rates of the prostheses in the two groups were 100%.ConclusionFor severe medial compartment OA, the early survival rates of the two prostheses are similar, but UKA has less traumatic, can preserve the normal structure of the knee, and the range of motion of the knee after operation is significantly better than TKA.
ObjectiveTo investigate the short-term effectiveness of unicompartmental knee arthroplasty (UKA) in the treatment of knee osteoarthritis of super-age patients over 85 years old.MethodsSenile patients with unilateral compartment osteoarthritis of the knee who received UKA between November 2013 and May 2017 and met the inclusion criteria were enrolled as the research objects. Among them, 40 patients (50 knees) were more than 85 years old (super-age group) and 44 patients (50 knees) were 52-81 years old (control group). There was significant difference in age between the two groups (t=17.33, P=0.00). There was no significant difference in body mass index, degenerative classification of medial and lateral compartments, varus deformity of knee, disease duration, complicating diseases, and preoperative hemoglobin, hematocrit (HCT), American Hospital for Special Surgery (HSS) score, range of motion (ROM) of knee, visual analogue scale (VAS) score, and femoral-tibial angle (FTA) between the two groups (P>0.05). Hospital stay, hemoglobin, and HCT of the two groups were recorded before operation and on the first day after operation. The changes of hemoglobin and HCT after operation were calculated. During follow-up period, the ROM of the knee, HSS score, and VAS score were measured; the position of the prosthesis and FTA were observed by X-ray films.ResultsThere was no significant difference in hospital stay between the two groups (t=1.05, P=0.29). Hemoglobin and HCT of the two groups on the first day after operation were significantly lower than those before operation (P<0.05). There was no significant difference in the postoperative changes of hemoglobin and HCT between the two groups (P>0.05). All the patients were followed up completely except 4 cases (5 knees) in the super-age group. The follow-up time ranged from 14 to 44 months of super-age group (mean, 29 months) and 21 to 33 months of control group (mean, 24 months). There were significant differences in HSS score, VAS score, ROM of the knee, and FTA between pre-operation and last follow-up in the two groups (P<0.05). There was significant difference in HSS score between the two groups (P<0.05), and no significant difference was found in ROM, VAS score, and FTA between the two groups (P>0.05). X-ray film showed no adverse position of the prosthesis, infection around the prosthesis, prosthesis loosening, or pathological bright lines.ConclusionUKA combined with reasonable perioperative management in the treatment of super-age patients over 85 years with knee osteoarthritis is safe and feasible, and can obtain satisfactory short-term effectiveness.
ObjectiveTo evaluate the short-term effectiveness of unicompartmental knee arthroplasty (UKA) for medial compartmental osteoarthritis of the knee.
MethodsBetween January 2008 and October 2013, 18 patients with medial compartmental osteoarthritis of the knee were treated by UKA, including 11 males and 7 females with an average age of 67.2 years (range, 60-72 years). The disease duration ranged from 3 to 5 years (mean, 3.7 years). All patients had loading pain and walk-associated pain of the medial compartmental knee. The preoperative visual analogue scale (VAS) score was 6.8±1.4. The full-length radiograph of lower limb and anteroposterior and lateral radiographs of the knee showed medial compartmental osteoarthritis of the knee. According to Ahlback staging, 8 knees were at stageⅡand 10 knees at stageⅢ. The knee range of motion (ROM) was (112.3±11.3)°, and the angle of genu varus was (13.2±1.3)°. The American Hospital for Special Surgery (HSS) score was 59.0±6.4.
ResultsPrimary healing of incision was obtained in all patients, and no infection or lower limb deep venous thrombosis occurred. All of the patients were followed up 6-50 months (mean, 28 months). No prosthetic loosening and dislocation or lesions of contralateral compartment and patellofemoral joint developed. At 6 months after operation, the VAS score was significantly reduced to 2.8±1.2 (t=9.20, P=0.00); most of patients achieved significant relief of pain. The HSS score was significantly increased to 92.0±3.1 (t=19.69, P=0.00); and the results were excellent in 12 cases, good in 5 cases, and poor in 1 case, with an excellent and good rate of 94.4%. The knee ROM was (115.2±10.2)°, showing no significant difference when compared with preoperative one (t=-0.81, P=0.23). The alignment of limbs showed that the angle of genu varus was significantly reduced to (6.8±2.1)° (t=10.99, P=0.00).
ConclusionUKA has satisfactory short-term effectiveness in the treatment of medial compartmental knee osteoarthritis, however, long-term effectiveness need further studies.
The surgical installation accuracy of the components in unicompartmental knee arthroplasty (UKA) is an important factor affecting the joint function and the implant life. Taking the ratio of the medial-lateral position of the femoral component relative to the tibial insert (a/A) as a parameter, and considering nine installation conditions of the femoral component, this study established the musculoskeletal multibody dynamics models of UKA to simulate the patients’ walking gait, and investigated the influences of the medial-lateral installation positions of the femoral component in UKA on the contact force, joint motion and ligament force of the knee joint. The results showed that, with the increase of a/A ratio, the medial contact force of the UKA implant was decreased and the lateral contact force of the cartilage was increased; the varus rotation, external rotation and posterior translation of the knee joint were increased; and the anterior cruciate ligament force, posterior cruciate ligament force and medial collateral ligament force were decreased. The medial-lateral installation positions of the femoral component in UKA had little effect on knee flexion-extension movement and lateral collateral ligament force. When the a/A ratio was less than or equalled to 0.375, the femoral component collided with the tibia. In order to prevent the overload on the medial implant and lateral cartilage, the excessive ligament force, and the collision between the femoral component and the tibia, it is suggested that the a/A ratio should be controlled within the range of 0.427?0.688 when the femoral component is installed in UKA. This study provides a reference for the accurate installation of the femoral component in UKA.
【Abstract】 Objective To evaluate the mid-term effectiveness of Oxford Unicompartmental Knee system Phase III for medial unicompartmental knee osteoarthritis (OA). Methods Between December 2008 and August 2010, 26 patients (32 knees) with medial unicompartmental knee OA were treated. Of 26 patients, 11 were followed up more than 2 years, including 7 males and 4 females (14 knees, 6 left and 8 right knees) with an average age of 62.4 years (range, 50-74 years). All patients had load suffering and tenderness of medial unicompartmental knee, and complicated by varus deformity without limitation of flexion and extension; the disease duration ranged 5-23 years (mean, 11.6 years). According to Ahlback staging, 4 knees were at stage II and 10 knees at stage III. Cemented unicompartmental knee arthroplasty (Oxford Unicompartmental Knee system Phase III) was performed by minimally invasive technique. Results All the incisions were primary healing after operation. Five cases suffered from local ache in the pes anserinus during the first 3 months after operation, which was cured after conservative therapy. Of them, 11 patients were followed up 27.5 months on average (range, 24-30 months). During follow-up, no complication of prosthesis loosening, displacement, arthropathy in the opposite department, or the patellofemoral joint occurred. The range of motion was significantly improved from (109.2 ± 8.7)° preoperatively to (123.5 ± 6.7)° at last follow-up (P lt; 0.05); knee society score (KSS) and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) scores were all significantly improved (P lt; 0.05). At last follow-up, the femoro-tibial angle was significantly improved (P lt; 0.05); tibial plateau and the tibial anatomical axis increased, showing no significant difference (P gt; 0.05); and posterior tibial slope was significantly decreased (P lt; 0.05). Conclusion Oxford Unicompartmental Knee system Phase III has satisfactory mid-term effectiveness in treating medial unicompartmental knee OA with the advantages of little trauma and rapid recovery, but long-term effectiveness is expected for further follow-up.
ObjectiveTo compare the patient-reported outcomes regarding function, joint amnesia, and the quality of life after unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA). Methods The clinical data of patients who received UKA or TKA between September 2017 and June 2018 were retrospectively analyzed. After propensity score matching, 40 patients (40 knees) each in TKA group and UKA group were finally included in the study. There was no significant difference between the two groups in gender, age, body mass index, surgical side, preoperative knee range of motion, Western Ontario and McMaster University Osteoarthritis Index (WOMAC) score, clinical and function scores of knee society score (KSS) (P>0.05). At 2 years after operation, WOMAC score, KSS clinical and function scores were performed on the two groups of patients, and compared with preoperative ones; knee injury and osteoarthritis outcome score-physical function short form (KOOS-PS), short-form 36 health survey scale (SF-36 scale), and forgotten joint score (FJS) were also performed. Results At 2 years after operation, the total score of WOMAC, the clinical and function scores of KSS in the two groups significantly improved when compared with preoperative ones (P<0.05), but there was no significant difference in the total score of WOMAC, the individual score of WOMAC, the clinical and function scores of KSS between the two groups (P>0.05). The total KOOS-PS score in the UKA group was significantly lower than that in the TKA group (t=4.243, P=0.000), and the scores of writhing/knee rotation, kneeling, and squatting in the UKA group were significantly lower than those in the TKA group (P<0.05). The total FJS score in the UKA group was significantly higher than that in the TKA group (t=?6.334, P=0.000). In the UKA group, the scores of 7 items were significantly lower than those of the TKA group (P<0.05) including when walking over 15 minutes, when climbing stairs, when walking on uneven ground, when standing for long periods, when doing housework or gardening, when taking a walk or hiking, and when doing your favorite sport. The SF-36 scales of physiological function, energy, social function, emotional function, and mental health in the UKA group were significantly higher than those in the TKA group (P<0.05). Conclusion Compared with TKA, patients treated with UKA may have better knee function recovery, joint amnesia, and higher quality of life.
ObjectiveTo summarize research progress of change in bone mineral density (BMD) after knee arthroplasty and its diagnostic methods, influencing factors, and drug prevention and treatment.MethodsThe relevant literature at home and abroad was reviewed and summarized from research status of the advantages and disadvantages of BMD assessment methods, the trend of changes in BMD after knee arthroplasty and its influencing factors, and the differences in effectiveness of drugs.ResultsThe central BMD and mean BMD around the prosthesis decrease after knee arthroplasty, which is closely associated with body position, age, weight, daily activities, and the fixation methods, design, and material of prosthesis. Denosumab, bisphosphonates, and teriparatide et al. can decrease BMD loss after knee arthroplasty.ConclusionBMD after knee arthroplasty decreases, which is related to various factors, but the mechanism is unclear. At present, some inhibitors of bone resorption can decrease BMD loss after knee arthroplasty. However, its long-term efficacy remains to be further explored.
ObjectiveTo conclude the revision reason of unicompartmental knee arthroplasty (UKA) using computer-assisted technology so as to provide reference for reducing the revision incidence and improving the level of surgical technique and rehabilitation.
MethodThe relevant literature on analyzing revision reason of UKA using computer-assisted technology in recent years was extensively reviewed.
ResultsThe revision reasons by computer-assisted technology are fracture of the medial tibial plateau, progressive osteoarthritis of reserved compartment, dislocation of mobile bearing, prosthesis loosening, polyethylene wear, and unexplained persistent pain.
ConclusionsComputer-assisted technology can be used to analyze the revision reason of UKA and guide the best operating method and rehabilitation scheme by simulating the operative process and knee joint activities.
