Minimally Invasive Surgical Group Research Articles

Comparison of minimally invasive approach versus conventional anterolateral approach for total hip arthroplasty: a randomized controlled trial

It is a general belief among hip surgeons that minimally invasive surgical (MIS) approach for implantation of a total hip arthroplasty (THA) allows an improved and faster postoperative rehabilitation because of reduced muscle and soft-tissue damage, less postoperative pain and blood loss, and shorter hospital stay compared with conventional approaches. In the published relative literature though, there are controversial reports and debates on this matter. To our knowledge, there is no study on the medium-term functional results comparing MIS and traditional approaches for total hip replacement. The purpose of this prospective comparative controlled study was to compare MIS with conventional approach, on terms of pain, blood loss, and functional recovery over a follow-up period of 4 years. In a total of 90 consecutive randomly selected adult patients, who suffered from unilateral primary hip osteoarthritis, a cementless Zweymüller-Plus THA (SL-Plus stem, Bicon screw socket) was implanted by a single senior orthopedic hip surgeon in one institution in the same period. Forty-five patients (group A) were operated using an MIS anterolateral, short incision, muscle-sparing approach and 45 (group B) with a conventional (anterolateral modified Watson-Jones) approach under partial detachment of gluteus medius and minimus. Anthropometric data, blood loss, short-form 36 questionnaire, visual analog scale pain score, and walking endurance were included in the analysis. Approach-related surgical complications (trochanter major fracture, Bicon malposition) were recorded. Data were collected postoperatively and at 4-year follow-up. Two patients of group A and eight patients of group B were excluded from the final analysis. Thus, 80 patients were eligible for the final evaluation 4 years postoperatively. Postoperative pain score was less in the MIS group. However, no differences in perioperative blood loss, functional outcome, and walking endurance were shown between groups. No difference in Bicon cup implantation angle was measured in postoperative roentgenograms between group A and B patients, no intraoperative trochanter fracture occurred in any patient of both groups. The present prospective randomized study revealed no significant mid-term clinical and functional benefit for patients who underwent a THA through an MIS in comparison with those who were managed with a conventional open approach.

Disc Space Preparation in Transforaminal Lumbar Interbody Fusion: A Comparison of Minimally Invasive and Open Approaches

Minimally invasive surgical (MIS) approaches to transforaminal lumbar interbody fusion (TLIF) have been developed as an alternative to the open approach. However, concerns remain regarding the adequacy of disc space preparation that can be achieved through a minimally invasive approach to TLIF. The purpose of this cadaver study is to compare the adequacy of disc space preparation through MIS and open approaches to TLIF. Specifically we sought to compare the two approaches with respect to (1) the time required to perform a discectomy and the number of endplate violations; (2) the percentage of disc removed; and (3) the anatomic location where residual disc would remain after discectomy. Forty lumbar levels (ie, L1-2 to L5-S1 in eight fresh cadaver specimens) were randomly assigned to open and MIS groups. Both surgeons were fellowship-trained spine surgeons proficient in the assigned approach used. Time required for discectomy, endplate violations, and percentage of disc removed by volume and mass were recorded for each level. A digital imaging software program (ImageJ; US National Institutes of Health, Bethesda, MD, USA) was used to measure the percent disc removed by area for the total disc and for each quadrant of the endplate. The open approach was associated with a shorter discectomy time (9 versus 12 minutes, p = 0.01) and fewer endplate violations (one versus three, p = 0.04) when compared with an MIS approach, percent disc removed by volume (80% versus 77%, p = 0.41), percent disc removed by mass (77% versus 75%, p = 0.55), and percent total disc removed by area (73% versus 71%, p = 0.63) between the open and MIS approaches, respectively. The posterior contralateral quadrant was associated with the lowest percent of disc removed compared with the other three quadrants in both open and MIS groups (50% and 60%, respectively). When performed by a surgeon experienced with MIS TLIF, MIS and open approaches are similar in regard to the adequacy of disc space preparation. The least amount of disc by percentage is removed from the posterior contralateral quadrant regardless of the approach; surgeons should pay particular attention to this anatomic location during the discectomy portion of the procedure to minimize the likelihood of pseudarthrosis.

Minimally Invasive Versus Open Sacroiliac Joint Fusion: Are They Similarly Safe and Effective?

The sacroiliac joint has been implicated as a source of chronic low back pain in 15% to 30% of patients. When nonsurgical approaches fail, sacroiliac joint fusion may be recommended. Advances in intraoperative image guidance have assisted minimally invasive surgical (MIS) techniques using ingrowth-coated fusion rods; however, how these techniques perform relative to open anterior fusion of the sacroiliac joint using plates and screws is not known. We compared estimated blood loss (EBL), surgical time, length of hospital stay (LOS), and Oswestry Disability Index (ODI) between patients undergoing MIS and open sacroiliac joint fusion. We retrospectively studied 63 patients (open: 36; MIS: 27) who underwent sacroiliac joint fusion with minimum 1-year followup at our institution from 2006 to 2011. Of those, 10 in the open group had incomplete records. All patients had sacroiliac joint dysfunction confirmed by image-guided intraarticular anesthetic sacroiliac joint injection and had failed nonoperative treatment. Patients were matched via propensity score, adjusting for age, sex, BMI, history of spine fusion, and preoperative ODI scores, leaving 22 in each group. Nine patients were not matched. We reviewed patient medical records to obtain EBL, length of surgery, LOS, and pre- and postoperative ODI scores. Mean followup was 13 months (range, 11-33 months) in the open group and 15 months (range, 12-26 months) in the MIS group. Patients in the open group had a higher mean EBL (681 mL versus 41 mL, p < 0.001). Mean surgical time and LOS were shorter in the MIS group than in the open group (68 minutes versus 128 minutes and 3.3 days versus 2 days, p < 0.001 for both). With the numbers available, mean postoperative ODI scores were not different between groups (47% versus 54%, p = 0.272). EBL, surgery time, and LOS favored the MIS sacroiliac fusion group. With the numbers available, ODI scores were similar between groups, though the study size was relatively small and it is possible that the study was underpowered on this end point. Because the implants used for these procedures make assessment of fusion challenging with available imaging techniques, we do not know how many patients' sacroiliac joints successfully fused, so longer followup and critical evaluation of outcomes scores over time are called for. Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

A meta-analysis of minimally invasive and conventional medial parapatella approaches for primary total knee arthroplasty

Minimally invasive surgical (MIS) approaches for total knee arthroplasty (TKA) have become increasingly popular for doctors and patients. They have argued that it decreases post-operative pain, accelerates functional recovery and increases patient satisfaction due to less injury. However, critics are concerned about TKA's possible effects on component position and with complications, considering the procedure's limited exposure. The purpose of this study was to summarise the best evidence in comparing the clinical and radiological outcomes between MIS and a conventional approach in TKA. Electronic databases were systematically searched to identify relevant randomised controlled trials (RCTs). Our search strategy followed the requirements of the Cochrane Library Handbook. Methodological quality was assessed, and data were extracted independently by two authors. Thirty studies, including 2,536 TKAs, were reviewed: 1,259 minimally invasive and 1,277 conventional exposure TKAs. The results showed that while the MIS group had longer operation times and tourniquet times, it had superior outcomes in KSS (objective and total), range of motion, flexion range of motion, flexion 90° day, straight leg-raising day, total blood loss and decrease in haemoglobin. However, wound-healing problems occurred more frequently in the MIS group. There were no statistically significant differences in other clinical or radiological outcomes between the MIS and conventional groups in TKA. The preliminary results indicate that the MIS approach provides an alternative to the conventional approach, with earlier rehabilitation but no malpositioning or severe complications. Wound-healing problems can be treated easily and effectively, and the risk also decreases as surgeons become more experienced, and more user-friendly instruments are invented. Potential benefits in medium- and long-term outcomes require larger, multicentre and well-conducted RCTs to confirm. Therapeutic study, Level II.

Minimally Invasive Total Knee Arthroplasty Does Not Improve Outcomes 1 Year after Surgery: A Randomized Controlled Trial

Background: Within the past few years, minimally invasive surgical (MIS) techniques fortotal knee arthroplasy (TKA) have emerged as promising alternatives to conventional TKA, possibly because of less surgical trauma to the quadriceps. The purpose of this investigation was to evaluate the efficacy of MIS TKA outcomes compared to conventional TKA. Methods: Forty-four patients, aged 50-85 years (64.3 ± 8.4 mean ± SD; 22 females, 22 males) who were scheduled for a unilateral TKA secondary to osteoarthritis were enrolled in a prospective randomized controlled trial. Patients were excluded if they had cardiopulmonary, neurological, or other unstable orthopedic conditions that limited function; uncontrolled diabetes; or a BMI ≥ 40 kg/m2. Patients were blinded and randomly assigned to one of two surgical groups: MIS or conventional. All patients completed a standardized course of rehabilitation following surgery. Patients were assessed preoperatively and 4, 12, 26, and 52 weeks postoperatively by a blinded evaluator; the 26- and 52-week outcomes are the focus of the present manuscript. Outcomes included isometric quadriceps strength (primary outcome), isometric hamstrings strength, quadriceps activation, active knee range of motion (AROM), the six-minute walk (6MW) test, pain at rest and with 6MW, timed-up-and-go test (TUG), the stair climbing test, the Short Form 36 Health Status questionnaire (SF-36) the Western Ontario and McMaster Osteoarthritis Index (WOMAC), and leg muscle mass. Results: There were no differences between groups at baseline. At 26 and 52 weeks postoperatively, there were no difference between MIS and control groups for any outcome measure. Conclusions: Although the MIS surgical technique for TKA may lead to faster recovery of strength in patients undergoing TKA (previously reported at 4 weeks postoperatively), there is no apparent benefit of MIS on the longerterm recovery of strength or functional performance. Therefore, the benefits of MIS TKA may not outweigh the risks associated with limited surgical visualization.

Open versus minimally invasive sacroiliac joint fusion: a multi-center comparison of perioperative measures and clinical outcomes

BackgroundSacroiliac (SI) joint pain is an under diagnosed source of low back pain due in part to lack of visible pathology on radiographs and symptoms mimicking other back-related disorders. Open SI joint fusion has been performed since the 1920s. This technique has fallen out of favor with the introduction of minimally invasive options. To date there has been no direct comparison between open and MIS SI joint fusion.MethodsWe conducted a multi-center, retrospective comparative cohort study of patients who underwent SI joint fusion using either an open surgical (OS) technique using a combination of screws and cages or a minimally invasive surgical (MIS) technique with a series of titanium plasma spray (TPS) coated triangular implants. Operative measures including surgical operating time, length of hospitalization and estimated blood loss (EBL) were collected along with demographics and medical history, surgical complications, and 12- and 24-month pain scores. Improvements in pain were compared after matching for age and gender and controlling for a history of lumbar spine fusion using repeated measures analysis of variance.ResultsData were available for 263 patients treated by 7 surgeons; 149 patients treated with OS and 114 treated with MIS SI joint fusion. Compared to OS patients, MIS patients were on average 10 years older (mean age 57 vs. 46) and 69% of all patients were female. MIS operative measures of EBL, operating time and length of hospitalization were significantly lower than open surgery (p < 0.001). Pain relief, measured as change from baseline to 12 months in VAS pain rating, was 3.5 points lower in the MIS vs. OS group (-6.2 vs. -2.7 points, p < 0.001). When matched for age, gender and a history of prior lumbar spinal fusion, postoperative pain scores were on average 3.0 points (95% CI 2.1 – 4.0) lower in MIS vs. OS (rANOVA p < 0.001).ConclusionsIn this multi-center comparative study, patients who underwent either OS or MIS SI joint fusion showed postoperative improvements in pain score. Compared to OS patients, patients who underwent MIS SI joint fusion had significantly greater pain relief and more favorable perioperative surgical measures.

Minimally invasive compared with open lumbar laminotomy: no functional benefits at 6 or 24 months after surgery

Background contextComparative studies between open and minimally invasive surgical (MIS) approaches for the treatment of spinal stenosis have mainly investigated immediate postoperative parameters. PurposeWe aimed to compare the postoperative improvements in functional and pain scores between open versus MIS lumbar laminotomy and to describe the complications of each method. Study design/settingWe conducted as retrospective review of prospectively collected data. Patient sampleWe included 113 patients. Outcome measuresVisual analog scale for back and leg pain, Oswestry Disability Index (ODI), the North American Spine Society score on neurogenic symptoms (NS), and average Short Form Health Survey-36 (SF-36) score. Accidental durotomies and patients with reoperations are presented. MethodsWe obtained a list of patients who underwent either MIS or open unilateral one-level lumbar laminotomy for the treatment of neural foraminal or lateral recess stenosis with unilateral leg NS. Outcome measures are presented at 6 and 24 months postoperatively. ResultsFrom 2000 to 2008, 113 patients (30 open, 83 MIS) underwent a one-level lumbar laminotomy and had complete postoperative data available for analysis. Between the approaches, there were no differences in baseline demographic data or functional scores. At 6 and 24 months after surgery, there were no differences in improvement in back or leg pain, or improvement in ODI, NS, or SF-36 scores. The MIS group reported greater satisfaction with treatment at 6 months (p=.009) but not at 24 months. Within the MIS group, three patients (3.6%) experienced an inadvertent durotomy and two patients (2.4%) underwent fusion of the operated segment within 24 months. ConclusionsCompared with an open approach, MIS lumbar laminotomy gave no clear advantages in longer term functional or pain scores. The MIS group also had patients with inadvertent durotomies and reoperation within 2 years. In any lumbar decompressive surgery, the purported advantages of an MIS approach should be carefully weighed against potential complications. For a relatively simple surgery such as laminotomy, the open approach remains a safe and straightforward option.

Outcomes of Minimally Invasive vs. Conventional Implantation of Continuous Flow Left Ventricualr Assist Device: A Single Center Experience

Purpose The use of left ventricular assist device (LVAD) as a bridge to transplant and for destination therapy is increasing. Conventional LVAD implantation (CON) is performed using a midline sternotomy. In some centers, LVADs are implanted with a minimally invasive surgical (MIS) approach using a mini-thoracotomy. However, little data exists comparing outcomes of these two techniques. Methods and Materials All Heartware continuous flow LVADS (HVAD) implanted at our institution were included in this analysis. We assessed the baseline characteristics and in-hospital as well as long terms outcomes (using INTERMACS definitions) in those who had CON vs. MIS implantation. Results Between May 2010 and Sept 2012, 40 HVADs were implanted. Of those, 15 (37%) were MIS and 25 (63%) were CON. Median length of support censored at time of transplantation was 149 days for MIS and 181 days for CON. The average age in the MIS group was lower than the CON group (48 vs. 57, p = 0.04), but other baseline characteristics were similar between the MIS and CON groups: male sex 60% vs 76%, ischemic etiology 33% vs 56%, INTERMACS 1 or 2 levels 80% vs 84% (P > 0.05 for all). Cardiopulmonary bypass time was shorter in MIS vs. CON (28.6 vs 70.0 min, p = 0.01). The average number of packed red cell transfusions in-hospital was similar between the two groups. The rates of complications using the INTERMACS definitions in MIS and CON groups were similar for the two groups: 20% vs 12% for renal dysfunction, 27% vs. 48% for respiratory failure, 40% vs 40% for major infection, and 20% vs 36% for neurologic dysfunction, respectively. Thirty-day and over-all mortality were 0% and 13% for MIS and 12% and 12% for CON, respectively (P > 0.05). Conclusions MIS implantation of HVAD is associated with similar risk of complications to CON implantation and there is no difference in short and long-term mortality. More rigorous trials are needed to assess the efficacy and safety of MIS implantation.

Minimally Invasive Total Knee Arthroplasty Improves Early Knee Strength But Not Functional Performance: A Randomized Controlled Trial

A prospective, randomized investigation compared early clinical outcomes of total knee arthroplasty (TKA) using conventional or minimally invasive surgical (MIS) approaches (n = 44). Outcome measures included isometric quadriceps and hamstrings strength, quadriceps activation, functional performance, knee pain, active knee range of motion, muscle mass, the Short Form-36, and Western Ontario and McMaster University Osteoarthritis Index, assessed preoperatively and 4 and 12 weeks after TKA. Four weeks after TKA, the MIS group had greater hamstring strength (P = .02) and quadriceps strength (P = .07), which did not translate to differences in other outcomes. At 12 weeks, there were no clinically meaningful differences between groups on any measure. Although MIS may lead to faster recovery of strength in patients undergoing TKA, there was no benefit on longer-term recovery of strength or functional performance.

Comparison of the minimally invasive and standard medial parapatellar approaches for primary total knee arthroplasty

The minimally invasive surgical (MIS) approach has been popularised as an alternative to the standard medial parapatellar approach (MPP) in total knee arthroplasty (TKA). Advocates of this technique suggest earlier functional recovery due to less injury to the surrounding tissues. Potential disadvantages however may include reduced overall exposure, component malalignment and damage to neurovascular structures. A systematic review and meta-analysis of randomised and quasi-randomised trials were conducted to compare the MIS and MPP approaches in primary TKA. Methodological features were rated independently by two reviewers. Seventeen studies were included involving 733 patients with mean age of 69 (SD ± 2.8) in the MIS group and 692 patients with mean age of 68.6 (SD ± 3.1) in the MPP group. Using a MIS approach led to significant increase in flexion within the first week after a TKA (mean difference (MD) of 9.9° (95% confidence interval (CI) 8.2-11.6, P < 0.01)). However, this effect was not sustainable at further follow-ups of ≥ 3 months. MIS showed a significantly increased risk of developing intraoperative complications with a risk ratio (RR) of 7.6 (95% CI 3.5-16.3, P < 0.01). MIS results in superior function in the immediate postoperative period after a primary TKA but is also associated with increased rates of intraoperative complications, and therefore, a standard approach that allows adequate exposure and avoids tension to the wound edges would be more appropriate to prevent such complications. Therapeutic study, Level I.

Clinical and biomechanical outcome of minimal invasive and open repair of the Achilles tendon

IntroductionWith evolutions in surgical techniques, minimally invasive surgical (MIS) repair with Achillon applicator has been introduced. However, there is still a lack of literature to investigate into the clinical merits of MIS over open surgery. This study aims to investigate the correlation between clinical outcome, gait analysis and biomechanical properties comparing both surgical methods.Materials and methodsA single centre retrospective review on all the consecutive operated patients between January 2004 and December 2008 was performed. Twenty-six patients (19 male and 7 female; age 40.4 ± 9.2 years) had experienced a complete Achilles tendon rupture with operative repair. Nineteen of the patients, 10 MIS versus 9 open repairs (13 men with a mean age of 40.54 ± 10.43 (range 23-62 yrs) and 6 women with a mean age of 45.33 ± 7.71 (range 35-57 yrs) were further invited to attend a thorough clinical assessment using Holz's scale and biomechanical evaluation at a mean of 25.3 months after operation. This study utilized the Cybex II isokinetic dynamometer to assess the isokinetic peak force of plantar-flexion and dorsiflexion of both ankles. The patients were also invited to return to our Gait Laboratory for analysis. The eight-infrared camera motion capture system (VICON, UK) was utilized for the acquisition of kinematic variables. Their anthropometric data was measured according to the Davis and coworkers' standard.ResultsThe mean operative time and length of hospital stay were shorter in the MIS group. The operative time was 54.55 ± 15.15 minutes versus 68.80 ± 18.23 minutes of the MIS group and Open group respectively (p = 0.045), whereas length of stay was 3.36 ± 1.21 days versus 6.40 ± 3.70 days respectively (p = 0.039). There is statistically significant decrease (p = 0.005) in incision length in MIS group than the open surgery group, 3.23 ± 1.10 cm versus 9.64 ± 2.55 cm respectively. Both groups attained similar Holz's scores, 11.70 ± 0.95 versus 12.0 ± 1.50 respectively (p = 0.262). The mean percentage stance time of the injured leg for MIS patient was 58.44% while the mean percentage stance time of the injured leg for patients with open repair was 56.57%. T-test has shown there were no significance differences between the results of the two groups of patients. The loss of peak torque and total work done with respect to the injured side were similar between the MIS and open group.Discussion and conclusionMIS using Achillon method can achieve smaller incisions, shorter operative time and hospital stay. There is no statistical significance difference in clinical outcome, the stance time to strike time ratio and biomechanical properties on the leg receiving Achilles tendon repair using MIS method and open surgery.

Cost-utility analysis of posterior minimally invasive fusion compared with conventional open fusion for lumbar spondylolisthesis

Background The utility and cost of minimally invasive surgical (MIS) fusion remain controversial. The primary objective of this study was to compare the direct economic impact of 1- and 2-level fusion for grade I or II degenerative or isthmic spondylolisthesis via an MIS technique compared with conventional open posterior decompression and fusion. Methods A retrospective cohort study was performed by use of prospective data from 78 consecutive patients (37 with MIS technique by 1 surgeon and 41 with open technique by 3 surgeons). Independent review of demographic, intraoperative, and acute postoperative data was performed. Oswestry disability index (ODI) and Short Form 36 (SF-36) values were prospectively collected preoperatively and at 1 year postoperatively. Cost-utility analysis was performed by use of in-hospital micro-costing data (operating room, nursing, imaging, laboratories, pharmacy, and allied health cost) and change in health utility index (SF-6D) at 1 year. Results The groups were comparable in terms of age, sex, preoperative hemoglobin, comorbidities, and body mass index. Groups significantly differed ( P < .01) regarding baseline ODI and SF-6D scores, as well as number of 2-level fusions (MIS, 12; open, 20) and number of interbody cages (MIS, 45; open, 14). Blood loss (200 mL vs 798 mL), transfusions (0% vs 17%), and length of stay (LOS) (6.1 days vs 8.4 days) were significantly ( P < .01) lower in the MIS group. Complications were also fewer in the MIS group (4 vs 12, P < .02). The mean cost of an open fusion was 1.28 times greater than that of an MIS fusion ( P = .001). Both groups had significant improvement in 1-year outcome. The changes in ODI and SF-6D scores were not statistically different between groups. Multivariate regression analysis showed that LOS and number of levels fused were independent predictors of cost. Age and MIS were the only predictors of LOS. Baseline outcomes and MIS were predictors of 1-year outcome. Conclusion MIS posterior fusion for spondylolisthesis does reduce blood loss, transfusion requirements, and LOS. Both techniques provided substantial clinical improvements at 1 year. The cost utility of the MIS technique was considered comparable to that of the open technique. Level of Evidence Level III.

Mini-Subvastus Approach for Total Knee Arthroplasty

The mini-subvastus surgical technique avoids both quadriceps arthrotomy and patella eversion. Since March 2003, this quad-sparing minimally invasive surgical (MIS) technique has been applied to more than 98% of our primary total knee arthroplasty (TKA) patients. This study compares our first 150 MIS TKA patients to our previous 150 traditional TKA patients. Quadriceps recovery was rapid in the MIS group with 83% able to do a straight leg raise the day after surgery. Hospital length of stay was decreased in the MIS group, 3.4 days, vs the traditional group, 4.1 days (P = .00013). Fewer MIS patients required skilled nursing or rehabilitation center admission. Increased knee flexion was seen for the MIS patients throughout the first 2 years of follow-up. Mean knee flexion at 1 year was 127° for the MIS patients vs 114° in the traditional TKA patients (P < .0001). Comparison between the MIS and traditional techniques demonstrated no increase in the number or severity of complications and no difference in operating room time.

Minimally invasive repair of pectus excavatum: A single institution's experience

Background. The Nuss repair of pectus excavatum is a relatively new, minimally invasive surgical (MIS) alternative to the traditional open “Ravitch-type” operation. We have one of the larger single-center experiences to date, and we conducted this clinical study to evaluate our early experience, emphasizing initial outcome and technical modifications designed to minimize complications. Methods. A retrospective chart review was performed on 112 patients who underwent 116 pectus excavatum repairs between January 1995 and January 2001. The Nuss procedure was performed in 80 patients, and open repair was performed in 32 patients. Information about demographics, deformity, operative course, complications, and early outcome was recorded. Results. Operative duration was 143 minutes for the open group and 53 minutes for the Nuss MIS group (P <.001). Blood loss was 6 mL/kg for the open group and 0.5 mL/kg for the MIS group (P <.001). Postoperative hospitalization was 3.2 days for the open group versus 3.7 days for the MIS group (P<.05). Conclusions. The MIS pectus repair can be performed safely with minimal blood loss and reduced operative time. Short-term analysis of the quality of repair, including absence of preoperative symptoms, patient satisfaction, and cosmetic appearance are encouraging. (Surgery 2001;130:652-9.)