Osteoarthritis with permanent dislocation of the patella treated by total knee arthroplasty through a lateral approach: A report of two cases

IntroductionPermanent dislocation of the patella (PDP) is a rare condition. In cases of PDP with tibiofemoral arthritis, total knee arthroplasty may be performed through a medial parapatellar approach with patellar realignment. In this article we present two cases of PDP with tibiofemoral osteoarthritis successfully treated via lateral approach TKA without any additional realignment procedure. We performed two total knee arthroplasties for PDP with lateral tibiofemoral arthritis through a lateral approach without any realignment procedure. Mobile bearing inserts were used to adjust rotational alignment. The patients showed improved functional outcomes (Japanese Orthopaedic Association Knee score and Oxford Knee Score), and improved range of motion. Three years postoperatively, the patellae remain stable without dislocation nor maltracking, maintaining a high functional score.ConclusionTo treat permanent dislocation of the patella with lateral knee osteoarthritis, TKA through a lateral approach have potential to be a new treatment option to achieve both a good outcome and repositioning of the patella.     

Posterior single-incision approach to minimally invasive total hip arthroplasty

Enhanced surgical techniques and instrumentation enable surgeons to perform total hip arthroplasties through minimally invasive approaches. Using incisions typically less than 10 cm in length, surgeons can achieve adequate visualization of the surgical site while minimizing trauma to deep soft tissues. Associated reductions in morbidity should allow for improved rehabilitation and recovery. Although these techniques have been met with some controversy, a number of recent studies appear to attest to their safety and efficacy. Many of these studies have concentrated on a posterior single-incision technique for total hip arthroplasty. Favorable results for such outcomes as operative times, complication rates, pain, functional recovery, and blood loss have been reported, and patient satisfaction has been high. If surgeons and their patients are to achieve maximum benefit from minimally invasive total hip arthroplasties, it will be necessary to design effective educational tools that address the learning curve associated with these approaches.     

Minimally invasive total knee arthroplasty using the contralateral knee as a control group: a case-control study

The primary purpose of this study was to compare clinical and functional results of bilateral total knee arthroplasties in which a conventional total knee replacement was initially performed on one knee and a minimally invasive total knee replacement was later performed on the contralateral side. Operative factors, clinical and radiographic outcomes, and quadriceps muscle strength were evaluated in twenty-five patients (50 total knee arthroplasties). Twenty-one of the 25 patients preferred the minimally invasive approach. Knee society objective scores and range-of-motion were significantly greater in the minimally invasive group. Isokinetic testing demonstrated statistically improved quadriceps muscle strength in the minimally invasive technique group compared to the standard approach at both 12 weeks and one year postoperatively. Radiographic analysis did not reveal differences in alignment variables between the two approaches. The results of this study suggest that minimally invasive total knee arthroplasty offers superior short-term as well as possible long-term results.     

Introduction of total knee arthroplasty in Lithuania: Results from the first 10 years

Background and purpose We have previously reported that the first 10 years of hip arthroplasty in Lithuania resulted in a higher cumulative revision rate than that observed in Sweden. We thus compared the corresponding results after introduaction of total knee replacement in Lithuania.Methods The 10-year revision rate for the first 595 primary ScanKnee arthroplasties inserted in Klaipeda, Lithuania, was compared to that for the first 1,280 ScanKnee primary arthroplasties inserted in Sweden. As in the hip replacement study, only patients with osteoarthritis (OA) were included. Primary knee arthroplasties without patellar resurfacing were included, and the endpoint was revision for any reason other than addition of a patellar component.Results We found that the cumulative revision rate was not statistically significantly different between the groups. The revision pattern was different, however, and we observed 24 isolated patellar component additions in Sweden, but none in Klaipeda.Interpretation Contrary to the results of our previous hip arthroplasty study, the cumulative revision rate after total knee arthroplasty was similar in the two groups. This suggests that compared to hip arthroplasty, the outcome of total knee arthroplasty was less dependent on surgical experience. The large difference regarding isolated patellar component additions may be explained by long-term accumulation of severe OA cases in Lithuania. To patients subject to a newly introduced surgical treatment offering great improvement in quality of life, patellofemoral pain may be a minor problem. Furthermore, patellar problems may not have seemed particularly relevant for the surgeons, considering the disability of other patients waiting to be treated.     

Design,operative technique and ten-year results of the Hermes™ patellofemoral arthroplasty

Purpose

Recently, increased interest has developed for patellofemoral arthroplasty as treatment for isolated patellofemoral arthritis. However, there are very few reports of the experience with the modern generation of patellofemoral arthroplasties. The new patellofemoral arthroplasty Hermes design is described. The design and technique of insertion are detailed.

Methods

The indications were isolated patellofemoral disease with advanced arthritic damage. Ten-year followup is available for treatment of 70 knees. Postoperative radiographs of patients were assessed for Oxford deterioration and maltracking of the patella. Tracking was categorised as follows: normal tracking, patellar subluxation, patellar dislocation.

Results

There were no late complications attributable to the arthroplasty. Disease progression in the tibiofemoral joint occurred in five patients requiring revision in three of these patients. Persistent anterior knee pain was recorded in four knees. The long-term results using this new design were better than those in the literature that described earlier designs, especially concerning malalignment. Only four knees in four patients had slight lateral patellar subluxation.

Conclusions

This implant offers a reasonable alternative to total knee replacement in patients with isolated patellofemoral disease.     

A randomized prospective study evaluating the effect of patellar eversion on the early functional outcomes in primary total knee arthroplasty

A prospective, randomized, blinded study was designed to investigate the impact of patellar eversion on early quadriceps function after total knee arthroplasty. One hundred twenty-two consecutive patients were randomized by 2 surgeons to receive one of 2 different surgical approaches. Surgeon A randomized patients to receive a mid-vastus split with or without patellar eversion. Surgeon B randomized patients to receive a median parapatellar arthrotomy or a mid-vastus split, both without patellar eversion. For surgeon A, a significantly earlier return of straight leg raise was noted when patellar eversion was avoided. Significant correlation existed between an earlier return of straight leg raise and decreased length of stay. Avoiding patellar eversion enhanced the return of quadriceps function and led to a decreased length of stay in the hospital.     

Lateral patellar contact after total knee arthroplasty: an analysis of the effects on postoperative pain and outcome

Although medialization of the patellar component during primary total knee arthroplasty (TKA) has been advocated for biomechanical reasons, this can lead to lateral patellar contact with the femoral component. Using blinded radiographic evaluations, we evaluated 980 consecutive primary TKAs performed from 1997 to 1998. The prevalence of lateral patellar contact in this series was found to be 46.1%. Lateral patellar contact was not correlated with significant differences in our measures of outcome (knee score [P = .1066], functional score [P = .2457], or range of motion [P = .2514]). The average pain score in knees with lateral patellar contact was higher (48.1) (less pain) when compared with knees without (46.7). Total knee arthroplasties without lateral patellar contact had a 1.61 times odds of experiencing postoperative pain compared with those TKAs with lateral patellar contact (P = .0025).     

Minimally invasive total knee arthroplasty compared with traditional total knee arthroplasty. Assessment of the learning curve and the postoperative recuperative period

BACKGROUND: There is disagreement about whether so-called minimally invasive approaches result in faster recovery following total knee arthroplasty. It is also unknown whether patients are exposed to excess risk during the surgeon's learning curve. We hypothesized that a minimally invasive quadriceps-sparing approach to total knee arthroplasty would allow earlier clinical recovery but would require longer operative times and compromise component alignment during the learning period compared with a traditional medial parapatellar approach. METHODS: The first 100 minimally invasive total knee arthroplasties done by a single high-volume arthroplasty surgeon were compared with his previous fifty procedures performed through a medial parapatellar approach, with respect to operative times, implant alignment, and clinical outcomes. Radiographic end points and operative times for the minimally invasive group were evaluated against increasing surgical experience, in order to characterize the learning curve. RESULTS: Overall, the minimally invasive approach took significantly longer to perform, on the average, than a medial parapatellar approach (86.3 and 78.9 minutes, respectively; p=0.01); this was the result of especially long operative times in the first twenty-five patients in the minimally invasive group (mean, 102.5 minutes). After the first twenty-five minimally invasive operations, no significant difference in the operative times was detected between the groups. The first twenty-five minimally invasive procedures had significantly less patellar resection accuracy (p<0.001) and significantly more patellar tilt than the last twenty-five (p=0.006). Other end points for implant alignment, including the frequency of radiographic outliers, were not different between the minimally invasive and traditional groups. The patients who had the minimally invasive approach demonstrated significantly better clinical outcomes with respect to the length of hospital stay (p<0.0001), need for inpatient rehabilitation after discharge (p<0.001), narcotic usage at two and six weeks postoperatively (p=0.001 and p=0.01, respectively), and the need for assistive devices to walk at two weeks postoperatively (p=0.025). CONCLUSIONS: A quadriceps-sparing minimally invasive approach seems to facilitate recovery, but a substantial learning curve (fifty procedures in the hands of a high-volume arthroplasty surgeon) may be required. If this experience is typical, the learning curve may be unacceptably long for a low-volume arthroplasty surgeon.     

Radiographic assessment in total knee arthroplasty

Sixty-five total knee arthroplasties were evaluated by the Knee Society Radiological Evaluation System which was developed to encourage uniform reporting of the results of total knee arthroplasty. All patients were examined by three independent experienced radiologists 8.9 years after surgery (range, 3-16 years) to analyze the interobserver variability. For measurement of angles, high interobserver correlation was calculated for the prosthetic component angles and the femorotibial shaft angle. The comparison of the means indicated no significant differences except for the femorotibial shaft angle. For measurement of radiolucent lines, interobserver correlation was low for all components. The differences of the means were significantly different for all components. The results of interobserver variability of the patellar evaluation revealed high interobserver correlation for the patellar angle and for patellar subluxation and dislocation evaluation. For assessment of patellar mediolateral and superoinferior displacement, a low interobserver correlation was found. For radiographic assessment of total knee arthroplasty, the measurement of angles, including alpha, beta, femorotibial shaft angle, sagittal femoral and tibial component angle, patellar angle, and patellar subluxation and dislocation evaluation are recommended. The method of assessing radiolucent lines should be reconsidered.     

Lateral patellofemoral impingement: a cause of treatable pain after TKA

Multiple etiologies may cause anterior knee pain after total knee arthroplasty. While prior studies have addressed component positioning and surgical technique, no series in the literature describes lateral patellofemoral impingement as a source of the pain. Over a 2-year period at our institution, 18 patients with 19 painful total knee arthroplasties were diagnosed with lateral patellofemoral impingement. All underwent revision surgery with either lateral facetectomy or revision of the patellar dome. These patients were followed with Knee Society scores for 1 year. Knee Society scores were significantly improved at 8 weeks, 16 weeks, and 1 year. Lateral patellofemoral impingement should always be considered in the differential diagnosis of the painful total knee arthroplasty. This should be evaluated clinically through direct palpation of the lateral facet, and radiographically with the sunrise view. Lateral facetectomy or patellar revision can be performed with predictably good clinical results.     

Results of MIS TKA at mean nine year follow-up

The first 103 consecutive minimally invasive total knee arthroplasties performed by a single surgeon were assessed to determine the clinical and radiographic outcomes at a mean of 9-year follow-up (range, 8 to 10 years). Patients who died before final follow-up were 10 (13 knees), leaving 90 knees in 69 patients for final review. Outcome was evaluated using Knee Society pain and functional scores. Survival with revision as an end point was 97.1%. Knee Society scores and range of motion improved significantly to a mean of 96 and 92 points and a mean of 115 degrees, respectively. There were five patients who required surgical intervention for unexplained pain with findings of retained cement and adhesions. Radiographic analysis did not reveal any progressive radiolucencies. These results suggest that excellent long-term outcomes can be achieved with minimally invasive total knee arthroplasty.     

Postoperative clinical outcome between lateral retraction and eversion of patella following simultaneous bilateral total knee arthroplasty

Aims and objectiveAmong the various exposure technique used in total knee arthroplasty (TKA); the midline medial parapatellar knee approach is most commonly performed; which require mobilisation of patella for adequate surgical exposure. In this study, we compare the effect of patellar eversion with lateral retraction in simultaneous bilateral TKA to find out difference in postoperative clinical outcome between the two patellar mobilisation techniques.MethodsWe enrolled 41 patients who underwent bilateral simultaneous TKR (82 knees) from Nov 2016 to Dec 2018. During surgery patellar eversion was done in one knee and lateral retraction was done in other knee selecting them randomly to reduce the bias. During the follow up period achieving unassisted active straight leg raise (SLR), 90 flexion and complications were recorded. Measurement of Oxford knee society score (OKSS), American knee society score (AKSS), Visual Analogue Scale (VAS) score, and quadriceps strength (measured by handheld dynamometer) was done daily up to one week, 1 month, 3 months, 6 months, and 1 year postoperatively.ResultsThe time of achieving active SLR and 901 flexion postoperatively was quicker in the lateral retraction group with a statistically significant difference. VAS pain score at 1 week and 1 month along with quadriceps strength in 1-month had statistically significant favourable outcomes in the lateral retraction group. Throughout the follow up lateral retraction group had better Oxford and American knee score but the difference being statistically insignificant. No significant difference was found on the complication rate.ConclusionIn comparison to lateral retraction, patellar eversion has an adverse effect in early knee functional recovery after TKA; it delays achieving active SLR, 901 flexion and has unfavourable outcome in functional scores, quadriceps strength, and postoperative pain relief. However it has minimal effects on long term functional outcomes.     

Lateral femoral sliding osteotomy in total knee arthroplasty for fixed valgus deformity

We treated 13 patients who had a fixed valgus deformity of the knee with a semi-constrained total knee arthroplasty combined with advancement of the lateral collateral ligament by means of a lateral femoral condylar sliding osteotomy. At follow-up of between 1 and 6.5 years, all patients were assessed using the Knee Society score. The mean knee score improved from 32 to 88 and the functional score from 45 to 73. The mean tibiofemoral angle was corrected from 191 to 180°. There was no postoperative tibiofemoral or patellar instability and, in most knees, distal transposition of the lateral femoral condyle achieved satisfactory stable alignment.     

Konventionelle Navigation ohne Computer und der laterale minimal-invasive Zugang beim kontrakten Valgusknie

Valgus arthritic knees can basically be operated on by either a standard medial or a specific lateral approach. The classic lateral approach according to Keblish has some advantages, but also some disadvantages, relative to the standard medial parapatellar approach. A less invasive lateral approach means that osteotomy of tibia tubercle and eversion of the patella is no longer necessary. In view of our positive experiences with the minimally invasive surgical technique used for implantation of the lateral unicondylar prosthesis and for total knee arthroplasty in the case of varus knees, we have developed a minimally invasive lateral technique for use in valgus knees. The approach is a modification of the classic lateral approach used by Keblish. The procedure involves a lateral mini-arthrotomy with no need for osteotomy of the tubercle or eversion of the patella, and the surgery takes place step by step from a lateral approach.Modified cutting standard instruments are used. All operations have been carried out using "conventional navigation" without computers. This consists in preoperative planning based on radiographs of the whole leg, intraoperative controls before and after bone cuts, planning of the rotational positioning of the femur and tibia and postoperative checks of the alignment on standing radiographs of the whole leg. Preliminary results observed in the first 63 consecutive patients (average age 45-85 years) with contract valgus deformity [average 12 degrees valgus (6-19 degrees )] are very promising. Since 2004 we have used minimally invasive medial and lateral mini-midvastus approaches routinely for nearly all our primary total knee arthroplasties.     

Patellofemoral complications with the Insall-Burstein II posterior-stabilized total knee arthroplasty

The Insall-Burstein and Insall-Burstein II posterior-stabilized (I-B II PS) prostheses have been reported to have a high prevalence of patellar complications. This is a prospective, consecutive study of 118 primary total knee arthroplasties in 82 patients with the I-B II PS prosthesis implanted by 1 surgeon, using a specific technique for patellar resurfacing. The mean follow-up time was 4.0 years (range, 2-8 years). Clinical evaluation was performed using a standard knee score system with specific additional evaluation of the patellofemoral joint. Radiographs were evaluated for fracture, loosening, and subluxation. Ninety-four knees (80%) were rated excellent, 21 knees (17%) good, and 3 knees (3%) fair. The mean flexion was 112 degrees postoperative. No knee required reoperation for the patellofemoral joint. There were 2 nondisplaced and 1 minimally displaced patellar fractures treated nonoperatively, no patellar clunk syndrome, and no subluxations. Using the patellar evaluation system, 109 knees had no anterior knee pain, 7 knees had mild pain, and 2 knees (1 patient) had moderate-to-severe pain only with rising from a chair. Patellofemoral crepitus with active flexion-extension in the seated position was noted in 16 knees (14%) but was painful in only 2 knees (1 patient). With this technique for patellar resurfacing with this prosthesis, patellofemoral complications were only 4.2%, and no knee required reoperation for the patella or for loosening. With attention to operative technique, patellofemoral resurfacing with this posterior-stabilized total knee arthroplasty can be highly successful.     

Functional disabilities and issues of concern for Asian patients before total ankle arthroplasty

Total ankle arthroplasty is a commonly performed invasive procedure that can be distressing to patients. Therefore, surgeons should consider patients' issues of greatest interest and concerns at the time of surgery and the function that patients hope to recover. Many studies have reported surgeon concerns before total knee arthroplasty and total hip arthroplasty, but few have focused on patients. The purpose of this study was to evaluate patients' functional disabilities and issues of concern regarding total ankle arthroplasty.Between May 2008 and June 2010, eighty-five patients (52 men and 33 women; mean age, 60 years) were recruited for the study. All patients were asked to complete a questionnaire divided into 3 parts: sociodemographic data, current functional disabilities and their perceived importance, and issues concerning patients before total ankle arthroplasty. Regarding functional disability based on severity, the top 5 issues were limping, difficulty squatting, daytime pain, difficulty kneeling, and difficulty climbing stairs. Regarding functional disability based on perceived importance, the top 5 issues were daytime pain, limping, difficulty walking, difficulty kneeling, and difficulty working. Regarding issues of concern, the top 5 issues were pain intraoperatively, ability to walk as much as desired, ability to climb stairs, pain after discharge from the hospital, and pain immediately postoperatively. The most important issue before total ankle arthroplasty was pain. Patients had a strong interest in high ankle extension and increased range of motion due to the lifestyle and religious activities of Eastern populations.     

Patellofemoral complications following total knee arthroplasty: Effect of a lateral release and sacrifice of the superior lateral geniculate artery

Between 1987 and 1989, 1,205 Anatomic Graduated Component (AGC, Biomet, Warsaw, IN) total knee arthroplasties were performed by three surgeons using the same prosthesis and same technique. Four hundred twenty-eight total knee arthroplasties (35%) had lateral releases; in 107 (75%) of these, the superior lateral geniculate artery was saved. Lateral release had no effect on patellar subluxation, dislocation, or loosening, but was associated with significantly more patellar fractures. Conversely, patellar radiolucency was more common in knees without a lateral release. Furthermore, saving the superior lateral geniculate artery during a lateral release had no effect on patellar dislocation, radiolucency, loosening, or fracture.