UniSpacer Arthroplasty of the Knee

Los Angeles Orthopaedic Institute, 4955 Van Nuys Boulevard, Suite 615, Sherman Oaks, California 91403, USA.
The Journal of Bone and Joint Surgery (Impact Factor: 5.28). 09/2005; 87(8):1706-11. DOI: 10.2106/JBJS.D.02339
Source: PubMed


The operative treatment of medial compartment knee arthritis is controversial. The purpose of the present study was to report the experience of a single surgeon with the UniSpacer arthroplasty for the treatment of isolated medial compartment arthritis of the knee.
From April 2002 through November 2002, thirty-seven UniSpacer arthroplasties were performed in thirty-four patients for the treatment of arthritis that primarily involved the medial compartment of the knee. The Ahlbäck radiographic evaluation scale was used to grade the severity of arthritis; the mean preoperative score was 2.6 points for the medial compartment and 0.5 point for both the lateral and patellofemoral compartments. The study group included eighteen women (nineteen knees) and sixteen men (eighteen knees) who had a mean age of fifty-five years (range, forty-two to seventy-five years) at the time of surgery. Twelve patients had had a previous arthroscopic meniscectomy. The mean preoperative Knee Society function score was 60 points (range, 40 to 80 points), and the mean preoperative Knee Society objective score was 62 points (range, 40 to 76 points).
After a mean duration of follow-up of twenty-six months (range, twenty-four to twenty-nine months), there were no excellent, ten good, fifteen fair, and twelve poor results. The mean postoperative total function score was 69 points (range, 40 to 82 points), and the mean Knee Society objective score was 72 points (range, 45 to 88 points). Six of the twelve poor results were in knees that had dislocation of the UniSpacer. All twelve knees were revised to a total knee arthroplasty.
On the basis of this experience, we do not recommend UniSpacer arthroplasty for the treatment of degenerative arthritis of the medial compartment of the knee.

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    • "Early interpositional devices utilized free-floating technology with anteroposterior motion of the implant and rotation during flexion and extension. However, the lack of appropriate fixation resulted in an unacceptably high number of device dislocations and revision surgeries.75–77 Extra-capsular (non-articular) medial compartment knee load absorber implants are currently under evaluation in clinical trials that require only a subcutaneous incision and provide device fixation at the medial distal femoral cortex and the medial proximal tibial cortex to achieve significant offloading of the medical compartment.78,79 "
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    ABSTRACT: Conservative management of medial compartment knee osteoarthritis (OA) is a misleading term used to describe the application of medical, orthotic, and/or rehabilitative therapies exclusive of surgical interventions. The implication of this nomenclature is that these therapies offer satisfactory symptom relief, alter disease progression, and have limited side effects. Unfortunately, conservative therapeutic options possesses few, if any, characteristics of an ideal treatment, namely one that significantly alleviates pain, improves knee function, and reduces medial compartmental loading without adverse side effects. As uncompensated mechanical loading is a primary culprit in the development and progression of knee OA, we propose that the therapeutic perspective of conservative treatment should shift from pharmacological treatments, which have no influence on joint loading, minimal potential to alter joint function, substantial associated risks, and significant financial costs, towards minimally invasive load absorbing therapeutic interventions. A safe and effective minimally invasive medical device specifically engineered for symptomatic relief of medial knee OA by limiting joint contact forces has the potential to reduce the clinical and economic knee OA burden. This review characterizes the current standard of care recommendations for conservative management of medial compartment knee OA with respect to treatment efficacy, risk profile, and economic burden.
    Full-text · Article · Feb 2013 · Orthopedic Reviews
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    • "Furthermore, PRP procedures are being abused by some hospitals as a means of unjust profit-making and hospital advertisement, which can transfer relative disadvantages to the majority of medical institutions that follow honest evidence-based medicine. It is important to note that although some novel medical technologies develop and improve through critics and mistakes, many are discarded due to problems in safety and validity6,7). "
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    ABSTRACT: Platelet-rich plasma (PRP) is a concentrate extract of platelets from autologous blood, and represents a possible treatment option for the stimulation and acceleration of soft-tissue healing and regeneration in orthopedics. Currently, the availability of devices for outpatient preparation and delivery contributes to the increase in the clinical use of PRP therapy in practical setting of orthopedic fields. However, there is still paucity of scientific evidence in the literature to prove efficacy of PRP therapy for the treatment of ligament or tendon problems around the knee joint. Moreover, strong evidence from well-designed clinical trials to support the PRP therapy for osteoarthritis of the knee joint is yet scanty in the literature. Scientific studies need to be performed to assess clinical indications, efficacy, and safety of PRP, and this will require high powered randomized controlled trials. Nonetheless, some hospitals exaggeratedly advertise PRP procedures as the ultimate treatment and a novel technology with abundant scientific evidence for the treatment of knee problems. As a matter of fact, PRP protocols are currently approved only for use in clinical trials and research, and are not allowed for treatment purpose by any institutions in Korea. At present, clinical use of PRP therapy for ligament or tendon problems or osteoarthritis of knee joint is defined as illegal medical practice, regardless of whether it is performed as a sole procedure or as a part of prolotherapy, because the safety and validity are not yet approved by the Ministry of Health and Welfare and Health Insurance Review and Assessment Service. Practicing physicians should remember that injection of PRP to patients by imposing medical charge is still illegal as per the current medical law in Korea.
    Full-text · Article · Jun 2012
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    • "Use of the UniSpacer™ in unicompartmental OA was initially recommended for young and active patients (Hallock & Fell, 2003). The role of this procedure still is not certain as it has been considered suitable for only few patients (1%) (Scott & Deshmukh, 2005) and there have been reports of poor postoperative results due to implant dislocation (up to 44%) (Bailie et al., 2005; Sisto & Mitchell, 2005). Clarius et al. showed in their study a significant, slightly over-adjusting, correction of moderate varus alignment by UniSpacer™ arthroplasty, which does not correlate with the thickness of the implant used (Clarius et al., 2003). "

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