Arterial and lymphatic supply of the knee integuments

Total Infrapatellar Fat Pad Excision Leads to Worse Isokinetic Performance in Total Knee Arthroplasty: A Randomized Controlled Trial

There are concerns that total infrapatellar fat pad (IPFP) excision in total knee arthroplasty (TKA) results in patellar tendon shortening due to ischemic contracture, but individual preference of the surgeon is still the main determinant between total or partial excision. The aim of this randomized controlled study was to compare isokinetic performance and clinical outcome of TKAs with total and partial excision of the IPFP. Seventy-two patients scheduled to undergo TKA for primary knee osteoarthritis by a single surgeon were randomly assigned to either total or partial excision group. Patients were evaluated preoperatively and at postoperative 1 year, with Knee Society Score (KSS) and isokinetic measurements. The physiatrist performing isokinetic tests and patients were blinded to the study. There were no significant differences between the groups in respect of age, body mass index, gender, and preoperative KSS and isokinetic performance. Postoperatively, both groups had improved KSS knee and KSS function scores, with no difference determined. Knee extension peak torque was significantly higher postoperatively in the partial excision group at postoperative 1 year (p = 0.036). However, there were no significant differences in knee flexion peak torque following TKA (p = 0.649). The results of this study demonstrated that total excision of the IPFP during TKA is associated with worse isokinetic performance, which is most likely due to changes in the knee biomechanics with the development of patella baja. Partial excision of the IPFP appears to be a valid alternative to overcome this potential detrimental effect without impeding exposure to the lateral compartment. This is a Level I, therapeutic study.

Arthroscopic-assisted robotic bi-unicompartmental knee arthroplasty: a pilot cadaveric study

INTRODUCTION

Although bicondylar arthroplasty showed great functional results, it encounters some difficulties to be performed routinely. On the other hand, arthroscopic techniques tend to replace open surgical techniques in sports medicine but strive to be developed in the field of arthroplasty. This study aimed to assess the feasibility of a micro-invasive bi-compartmental knee arthroplasty using both arthroscopic and robotic technologies (A-BiUKA).

MATERIALS AND METHODS

The study was conducted on complete fresh-frozen and embalmed cadaveric specimens. The main criterion of judgment was the successful positioning of trial implants through a minimal quad-sparing approach. Arthroscopy was used for bone-morphing and burring, supported by an image-free robotic system. Secondary criteria of judgment were axial deviation (measured using the navigation system), operating time, and incision length.

RESULTS

Ten A-BiUKA were performed. Implantation was successful in all cases. The mean preoperative frontal deviation was 179.8° ± 3.2 [175: 185], the mean postoperative frontal deviation was 178.5° ± 2.2 [175: 182], without any outliers. The mean correction was 1.7° ± 1.6 [0: 5]. Once the eight first A-UKA were performed, constituting the learning curve, the mean operative time for the remaining twelves surgeries was 90 min ± 6. The mean skin incision length was 3.35 cm ± 0.13 [3: 4].

CONCLUSION

Associated arthroscopic and robotic technologies allows to perform Bi-UKA procedure using a quad sparing mini-invasive approach. Clinical prospective studies have to confirm the feasibility and the clinical outcomes of this surgery.

Staged vs Concurrent Hardware Removal During Conversion Total Knee Arthroplasty

BACKGROUND

Conversion total knee arthroplasty (TKA) in the presence of periarticular hardware can be associated with increased resource utilization, complications, and revisions. However, little guidance exists on the optimal approach to hardware removal. The purpose of this study is to compare outcomes of conversion TKA with hardware removal performed in either a staged or concurrent manner.

METHODS

This is a retrospective study of 155 TKA operations performed with staged (45) or concurrent (110) removal of hardware at the time of TKA. Differences in patient data, case data, complications, reoperations, and revisions were evaluated. Subgroup comparisons of cases involving major hardware (plates, nails, rods), minor hardware (screws, buttons, wires), and tibial plates were performed.

RESULTS

There were no differences in age, sex, body mass index, or comorbidities between patients who underwent staged or concurrent hardware removal. Rates of complications, reoperations, and revisions did not differ at multiple time points (90 days, 1 year, 2 years, 4 years). Patients who underwent staged hardware removal were more likely to have had prior surgery for fracture reconstruction (68% vs 33%, P < .001), to have had major hardware removed (84% vs 59%, P = .03), and were less likely to have had hardware removal performed through a single incision with TKA (50% vs 92%, P < .001). Subgroup analysis of major and minor hardware cases demonstrated comparable outcomes.

CONCLUSION

There remains no established benefit to either a staged or concurrent approach to hardware removal at the time of TKA. This is true regardless of hardware burden. At this time, a case-by-case approach should be taken to conversion TKA in the presence of periarticular hardware.

Influence of the Infrapatellar Fat Pad Resection during Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

Background

To enhance surgical exposure, resection of the infrapatellar fat pad (IPFP) is usually a routine procedure in total knee arthroplasty (TKA). However, there is conflicting evidence regarding whether IPFP resection during TKA impairs clinical outcome. We performed a systematic review and meta-analysis to clarify the influence of IPFP resection on primary TKA.

Methods

Embase, PubMed, and the Cochrane Library were systematically searched up to August 2016 to identify relevant studies. All clinical studies comparing IPFP resection (IPFP-R) and IPFP preservation (IPFP-P) in patients undergoing primary TKA were obtained. The meta-analysis was performed with Revman 5.3 and STATA 12.0 software. The weighted mean was estimated by using random effects (RE) models with 95% CIs, heterogeneity was assessed using the H statistic and the inconsistency index (I²).

Results

Seven studies involving 2,734 patients (3,258 knees) were included. IPFP resection trended to increase the incidence of postoperative anterior knee pain within 2 months postoperatively, compared with patients in whom the IPFP was preserved (odds ratio [OR]s 2.12[0.95, 4.73], p = 0.07). An increased incidence of anterior knee pain was observed in the IPFP resection group > 12 months postoperatively, but the difference was not significant (OR, 3.69 [0.81, 16.82], p = 0.07). In addition, a trend towards more shortening of the patellar tendon was also observed in the IPFP-R group. No significant results were found regarding postoperative knee function.

Conclusion

These results suggest that preserving the IPFP may be superior to IPFP resection in patients undergoing primary TKA, due to the relatively lower rate of anterior knee pain after short-term follow-up.

The surgical approach for revision total knee arthroplasty

A key to the success of revision total knee arthroplasty (TKA) is a safe surgical approach using an exposure that minimises complications. In most patients, a medial parapatellar arthrotomy with complete synovectomy is sufficient. If additional exposure is needed, a quadriceps snip performed through the quadriceps tendon often provides the additional exposure required. It is simple to perform and does not alter the post-operative rehabilitative protocol. In rare cases, in which additional exposure is needed, or when removal of a cemented long-stemmed tibial component is required, a tibial tubercle osteotomy (TTO) may be used. Given the risk of post-operative extensor lag, a V-Y quadricepsplasty is rarely indicated and usually considered only if TTO is not possible.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):113–15.

UPDATING OF THE ANATOMY OF THE EXTENSOR MECHANISM OF THE KNEE USING A THREE-DIMENSIONAL VIEWING TECHNIQUE

The knee extensor mechanism is a complex structure formed by the quadriceps muscle and tendon, the patella, the patellar tendon and the ligaments that surround and help stabilize the knee. Through using a three-dimensional viewing technique on images of the knee extensor apparatus, we aimed to didactically show the structures that compose this bone-muscle-ligament complex. Anatomical dissection of the knee with emphasis on the structures of its extensor mechanism was performed, followed by taking photographs using a camera and lenses suitable for simulating human vision, through a technique for constructing three-dimensional images. Then, with the aid of appropriate software, pairs of images of the same structure from different angles simulating human vision were overlain with the addition of polarizing layer, thereby completing the construction of an anaglyphic image. The main structures of the knee extensor mechanism could be observed with a three-dimensional effect. Among the main benefits relating to this technique, we can highlight that in addition to teaching and studying musculoskeletal anatomy, it has potential use in training for surgical procedures and production of images for diagnostic tests.

Does infrapatellar fat pad resection in total knee arthroplasty impair clinical outcome? A systematic review

INTRODUCTION

The infrapatellar fat pad (IPFP) is often removed during total knee arthroplasty (TKA). No evidence based guidelines on changes in clinical outcome have yet been described. The aim of this review is to investigate whether regular removal of the IPFP during TKA should be performed.

MATERIAL AND METHODS

Seven databases were systematically searched. Clinical studies, in which TKA with IPFP resection was compared with IPFP preservation, were included. Risk of bias was assessed using the Cochrane collaboration tool. Studies reporting anterior knee pain, patellar tendon length, range of motion, patellar vascularisation or functional outcome were included.

RESULTS

The indication for TKA varied in the different studies: osteoarthritis (OA), rheumatic arthritis (RA) and multiple indications (OA, RA and osteonecrosis). After IPFP resection: 1. For OA, no differences in function, range of motion, and anterior knee pain were found. 2. In the RA study, there was a trend towards more discomfort and a decrease in function. 3. In OA and RA patients a decrease in patellar tendon length was observed. 4. One study reported no decrease in patellar vascularisation.

DISCUSSION

Limitations of this review are the high risk of bias scores of the included studies, the varying outcome measures, follow up, number and type of participants. Randomised clinical trials are required to support or refute the results, contributing to a possible future evidence based guideline on IPFP resection during TKA.

Transcutaneous oxygen tension in the anterior skin of the knee after minimal incision total knee arthroplasty

BACKGROUND

Delayed wound healing after total knee arthroplasty (TKA) can lead to devastating complications. The lateral flap is reported to be more hypoxic than the medial flap in conventional TKA. However, the surgical approach significantly affects the cutaneous blood supply. Our hypothesis was that postoperative oxygenation of the skin over the anterior knee would be different in minimal incision TKA.

METHODS

This prospective observation study included 21 patients who underwent minimal incision TKA. Transcutaneous oxygen tension (TcPO2) was measured perioperatively at four sites around the midline incision: superio-medial, superio-lateral, inferio-medial, and inferio-lateral. The ratio of the regional TcPO2 to the reference TcPO2 was calculated as the regional perfusion index (RPI). We compared the RPI among four sites and evaluated the association between the RPI and wound healing.

RESULTS

At all measurement sites, the RPI significantly decreased after surgery (days 1 and 7; p<0.01). On day 7, the RPI at inferio-medial and inferio-lateral sites were significantly lower than superio-medial and superio-lateral sites, respectively (p<0.05). No significant difference between the medial and lateral sites was observed. In three patients, delayed healing was noted at the inferio-lateral wound edge, where the RPI significantly decreased on day 1.

CONCLUSION

The distal part of the wound was significantly more hypoxic than the proximal part in minimal incision TKA. Atraumatic wound edge retraction should be carried out especially in the distal part. Although further investigation is necessary, delayed wound healing is potentially associated with regional skin hypoxia on day 1.

Unilateral or bilateral V-Y fasciocutaneous flaps for the coverage of soft tissue defects following total knee arthroplasty

Background

Soft tissue necrosis following total knee arthroplasty (TKA) may be the cause of the devastating complication of deep infection. It necessitates an immediate operative intervention because it could potentially jeopardise the arthroplasty or even the limb.

Methods

Sixteen consecutive patients with a mean age of 73,8 years (range 47 to76 years) over a 6-year period (January 2003 to December 2008) with wound dehiscence after TKA were enrolled in the present study. Unilateral or bilateral fasciocutaneous V-Y flaps that are differently oriented, depending on the local conditions of the tissues were used to reconstruct the soft tissues defects.

Results

In 15 of the 16 cases studied, the wound was successfully covered with the presented technique while in 1 patient a partial flap loss occurred, which was healed after surgical debridement and the application of vacuum system. No other complications occurred. Knee prosthesis was salvaged in all the patients with a good functional and esthetical outcome.

Conclusions

The presented reconstructive technique is a simple, quick, versatile and reliable solution for the coverage of soft tissue defects following TKA, more than 2 cm width and grade 1 and 2 according to Laing classification, provided the V-Y flaps are applied early in the postoperative period and no complex defects are involved.

Wound complications after total knee arthroplasty

Some wound complications can be prevented with attention to patient, surgical, and postoperative factors; others develop despite all efforts. Some practices that affect wound healing, such as the use of drains and methods of thromboprophylaxis are contentious. Superficial wound problems must always be discriminated from deep infection, which is not the focus of this article. Wound complications require prompt attention. As there is little morbidity from early irrigation and debridement of problem total knee arthroplasties (Weiss AP, Krackow KA. Persistent wound drainage after primary total knee arthroplasty. J Arthroplasty. 1993;8(3):285-9), early intervention is generally preferred.

Wound problems in total knee arthroplasty

Wound problems can often be prevented with careful planning. When transverse incisions are used for knee surgery many years prior to any anticipated knee arthroplasty, no major problems are typically encountered with a conventional, anterior longitudinal incision. We recommend lateral incisions (eg, after a previous lateral tibial plateau fracture) be reused for TKA. When confronted with multiple previous incisions, surgeons would best use the most recently healed or the most lateral. We prefer soft tissue reconstruction with expanders or a gastrocnemius flap if there are multiple incisions, if the skin and scar tissue are adherent to underlying tissue, or if wound healing seems questionable. Deep infection must be determined by aspiration. When present, we believe treatment must include irrigation, débridement, polyethylene exchange if acute, and resection arthroplasty if chronic. Poor wound healing is a potentially devastating complication that may result in multiple reconstructive procedures and even amputation. Early recognition followed by expeditious débridement and soft tissue reconstruction should be used for managing wound complications after TKA.

Surgical exposures in revision total knee arthroplasty

Safely obtaining adequate exposure at the time of revision total knee arthroplasty is an integral step in successfully performing the procedure. A medial capsular approach combined with an extensive intraarticular synovectomy provides adequate exposure for most patients. If further exposure is required, a quadriceps snip can be used to free the proximal extensor mechanism. The benefits of this approach include its technically simple nature and an unaltered postoperative rehabilitation regimen. We report a series of 126 consecutive revision knee procedures in which a medial capsular approach was adequate in 111 cases, representing 92% of the patients with an intact extensor mechanism. A quadriceps snip was required in nine cases. If more extensive exposure is required for an excessively stiff or difficult to expose knee, a tibial tubercle osteotomy or V-Y quadricepsplasty provides wider exposure.

LEVEL OF EVIDENCE

Therapeutic study, level IV (case series). See the Guidelines for Authors for a complete description of levels of evidence.

A review of wound healing following Maquet osteotomy

Maquet osteotomy can be associated with an unacceptably high incidence of wound complications that may be as high as 37%. A consecutive series of 42 Maquet osteotomies has been performed between 1990 and 2002 by a single surgeon without a single wound problem or infection and this series is the subject of this report. The use of an anterolateral incision reduces the damage to the major lymphatics minimising the risk of wound oedema. Identification and preservation of the feeding musculocutaneous vessels on the lateral and medial sides facilitates extensive but safe mobilisation of the skin flaps permitting an easy closure over a substantially elevated tibial tubercle. The use of an anterolateral incision with knowledge of the blood supply of the leg has eliminated the wound complications associated with the standard anteromedial incision reported previously in the literature. This approach, preserving the blood supply and lymphatic drainage, avoids skin necrosis and wound dehiscence, obviates any requirement for plastic surgical procedures such as releasing incisions or skin grafts and minimises the risk of infection and osteomyelitis.