AAOS Now

Published 8/1/2011

Board takes professional compliance actions

At its meetings on April 25, 2011 and June 11, 2011 the Board of Directors of the American Association of Orthopaedic Surgeons (AAOS) considered grievances filed under the AAOS Professional Compliance Program that alleged violations of the AAOS Standards of Professionalism (SOPs) for Orthopaedic Expert Witness Testimony. After considering the information presented and upon recommendations of the Judiciary Committee and/or the Grievance Hearing Panel of the Committee on Professionalism (COP), the Board took the professional compliance actions indicated.

Edward M. Decter, MD
West Orange, NJ
Censured

On September 1, 2006, a grievance was filed against Dr. Decter alleging violations of Mandatory Standards 1, 2, 3, and 7 of the AAOS Standards of Professionalism for Orthopaedic Expert Witness Testimony. The grievance arose from statements made by Dr. Decter in his prepared written report of medical opinion, deposition, and testimony. Dr. Decter was an expert witness in a case alleging that a patient, who had sustained a work-related injury, was allowed to resume unrestricted work activity too soon causing her to suffer progression of disk pathology resulting in permanent radiculopathy despite surgical intervention.

The patient in this case was a 46-year-old nurse who injured her back at work on May 10, 2001, while pulling a patient. She was evaluated by the Grievant 1 week later. She had reported a similar injury 8 years previously and was then out of work for 1 week. At the time of evaluation she complained of pain in the low back with occasional radiation to the right mid thigh but no further distal. There were no complaints of numbness or paresthesias and straight leg raising caused back pain, but no leg pain. Neurologic examination was normal and she was diagnosed with an acute back sprain. She was referred for physical therapy and advised to be out of work.

Improvement continued and she was allowed to return to work on May 31 but noted worsening of her pain. An MRI was obtained and revealed small disk herniations without nerve root impingement. Because she continued to improve, she was allowed to return to work on June 11 and advised to continue her home exercise program.

By late August clear-cut radicular symptoms and findings had developed on the right side, and a sneezing episode had precipitated left-sided weakness as well. An MRI now confirmed significant disk herniations with progression at two levels and surgical decompression was undertaken. Although she had initial improvement following surgery, by March 2003, she continued to show residual left lower extremity weakness.

On June 1, 2007, the Grievance Hearing Panel of the AAOS Committee on Professionalism (COP) conducted a hearing at which Dr. Decter was present. He was accompanied by legal representation and witness on his behalf. After careful review, the COP Grievance Hearing Panel found that Dr. Decter had violated Mandatory Standards 2, 3, and 7 but not Mandatory Standard 1.

In making its recommendations, the COP Grievance Hearing Panel considered all material submitted and determined that Dr. Decter did not provide opinions and factual testimony in a fair and impartial manner. He was found to have made contradictory statements regarding when the patient actually sustained a herniated disk as well as at what point in time the healing process begins. The COP Grievance Hearing Panel also determined that Dr. Decter did not evaluate the medical condition and care provided in light of generally accepted standards at the time, place, and in the context of care delivered.

The Panel found that Dr. Decter did not base his opinion on the available scientific evidence when he opined that the standard of care for a disk herniation was to remove the patient from the workplace for a 6-week period to allow the annulus to heal. Dr. Decter admitted that there was no orthopaedic literature to support his opinion. He based his opinion, in part, on the fact that it takes other ligaments throughout the body 6 weeks to heal, but was unable to produce any literature to show that the annulus could be compared to other ligaments.

Dr. Decter appealed the findings and recommendation of the COP Grievance Hearing Panel. The Judiciary Committee conducted an appeal hearing in July 2008, and Dr. Decter attended with counsel. The Judiciary Committee determined that due process had been afforded to Dr. Decter and that the clear weight of evidence supported the COP Hearing Panel's recommendations.

On April 25, 2011, the AAOS Board of Directors considered this matter and voted to censure Edward M. Decter, MD, for violations of Mandatory Standards 2, 3, and 7 of the Standards of Professionalism for Orthopaedic Expert Witness Testimony

Warren A. Hammerschlag, MD
Hackensack, NJ
1-Year Suspension

On April 12, 2010, a grievance was filed against Warren A. Hammerschlag, MD, alleging violations of Mandatory Standards 1, 2, 5, and 8 of the Standards of Professionalism (SOPs) for Orthopaedic Expert Witness Testimony. On December 7, 2010, the AAOS Committee on Professionalism (COP) met in executive session and, having reviewed all submissions from both sides, determined that a prima facie case existed and that a hearing was warranted.

The grievance arose from statements made by Dr. Hammerschlag in his consultation report, letter of medical opinion, and deposition testimony as an expert witness. This case alleged that a patient, following total shoulder arthroplasty, had sustained permanent damage in the form of chronic pain and loss of function as a result of alleged malpositioning of the humeral component in 80 degrees of retroversion and an alleged failure to diagnose the excessive retroversion, both of which led to subsequent surgery and persistence of pain.

The patient in the underlying case was a 46-year-old truck driver who reportedly sustained an injury in September 2002 when, during a maneuver to connect his cab to a trailer, force was exerted against his right shoulder upon impact. He presented to the Grievant with reduced shoulder arc of motion and associated pain. Radiographs indicated degenerative arthritis and a subsequent MRI confirmed the degenerative changes.

The Grievant initially treated the patient with various nonsurgical measures. The patient remained unable to return to work and, in April 2003, he underwent a right total shoulder arthroplasty performed by the Grievant. The postoperative regimen included extensive physical therapy; however, the patient continued to complain of pain. After undergoing a functional capacity evaluation in April 2004, the patient was released to return to work. It appeared from the records that he was unable to continue working after September 2004 and the patient consulted with a second orthopaedic surgeon in November 2004.

This subsequent orthopaedist’s impression was that there was no instability and a provisional diagnosis of either glenoid loosening or possible rotator cuff pathology was considered. A computed tomography (CT) arthrogram was interpreted as indicating no full thickness tear of the rotator cuff and no gross loosening. The radiologist also noted that the humeral head component appeared to be well-positioned. In February 2005, the patient underwent surgery, which included diagnostic arthroscopy in an effort to identify the source of the problem.

No specific problems were identified and, consequently, an arthrotomy was performed. A decision to revise the humeral component was based on the belief that it was in “approximately 80 degrees of retroversion” and, additionally, that there was some posterior wear of the glenoid component. The surgery was complicated by a postoperative hematoma with concern for a possible infection and, 2½ weeks postoperatively, the patient underwent hematoma evacuation followed by intravenous antibiotic therapy. The subsequent treating orthopaedist continued to follow the patient through mid-May 2006 and, shortly afterwards, the patient was examined by the Respondent, Dr. Hammerschlag.

In his consultation report, Dr. Hammerschlag opined that the placement of the humeral component at 80 degrees of retroversion constituted a significant deviation from acceptable standards of care and contributed to the patient’s continued right shoulder symptoms, functional limitation, inability to perform his usual work-related duties, and the need for additional surgical treatment. Dr. Hammerschlag further stated in his expert letter of opinion that “the excessive malposition/retroversion would produce excessive posterior wear of the glenoid component,” and that such malposition, as well as the failure to diagnose the malposition, represented clear deviations from acceptable standards of care.

When asked to clarify his testimony that there had been a deviation in the standard of care by incorrectly inserting a prosthesis, Dr. Hammerschlag responded: “…my review of these records doesn’t indicate any reason for there to be any disbelief regarding [the subsequent treating orthopaedist’s] operative findings. [The orthopaedist] dictated a good operative report. It’s detailed. It’s appropriate regarding the procedures that he performed.”

In response to why he had, in his consultation report, omitted the radiologist’s findings that the humeral head component appeared well positioned, Dr. Hammerschlag replied: “…because that comment is disingenuous. That shows that according to the radiologist’s criteria, which is [sic] certainly not those of an orthopaedic surgeon, the prosthesis was within the humerus and was roughly within the position of the joint. He’s not commenting on the retroversion specifically. So there is no—and similarly even if you don’t want to believe my evaluation, [the subsequent treating orthopaedist] evaluated the CT arthrogram…So even if you find my interpretative abilities to be lacking, hopefully you won’t find his to be lacking.”

On February 18, 2011, the Grievance Hearing Panel of the AAOS Committee on Professionalism (COP) conducted a hearing at which the Grievant was present. Dr. Hammerschlag did not attend although he was given timely notice in accordance with the Professional Compliance Program Grievance Procedures. After thorough review and due deliberation, the COP Grievance Hearing Panel found that Dr. Hammerschlag had violated Mandatory Standards 2 and 8, but not Mandatory Standards 1 and 5. The COP Grievance Hearing Panel recommended that Dr. Hammerschlag be suspended from the AAOS for a period of 1 year.

In making its findings and recommendation, the COP Grievance Hearing Panel considered all submissions and the oral statements and responses provided at the grievance hearing. The COP Grievance Hearing Panel determined that Dr. Hammerschlag had relied exclusively on the subsequent orthopaedist’s observations regarding version without having directly examined the radiographs or giving any consideration to the validity of information from the Grievant.

In addition, the accuracy of the CT interpretation by the radiologist was categorically rejected by Dr. Hammerschlag. The COP Grievance Hearing Panel believed the CT images were very consistent with that report and supported appropriate version of the humeral component by the Grievant. The COP Grievance Hearing Panel found that in essence, Dr. Hammerschlag abdicated his role as an expert and, consequently, did not provide his testimony in a fair and impartial manner as required by Mandatory Standard 2.

In finding Dr. Hammerschlag in violation of Mandatory Standard 8, the COP Grievance Hearing Panel agreed that a general orthopaedic surgeon could have relevant experience and knowledge to testify in this type of case; however, the Hearing Panel determined that Dr. Hammerschlag’s testimony did not demonstrate that level of experience or knowledge.

Dr. Hammerschlag did not appeal the findings and recommendations of the COP Grievance Hearing Panel to the Judiciary Committee. On June 11, 2011, the AAOS Board of Directors considered the recommendation of the COP Grievance Hearing Panel and accompanying materials and voted to suspend Warren A. Hammerschlag, MD, for a period of 1 year due to violations of Mandatory Standards 2 and 8 of the Standards of Professionalism for Orthopaedic Expert Witness Testimony.

Stanley Soren, MD
Staten Island, NY
2-Year Suspension

On March 25, 2009, a grievance was filed against Stanley Soren, MD, alleging violations of Mandatory Standards 1, 3, 4, 5, 7, 8, 12, 13, and 15 of the Standards of Professionalism (SOPs) for Orthopaedic Expert Witness Testimony. The grievance arose from statements Dr. Soren made in deposition and trial testimonies as an expert witness in a medical liability lawsuit. The patient in this matter alleged he had undergone primary left total hip arthroplasty for uncomplicated osteoarthritis and, as a result, had allegedly sustained leg length inequality, foot drop and sciatic nerve injury. The legal case focused exclusively on the surgical procedure.

In his deposition, Dr. Soren stated that during a hip replacement procedure it was crucial to either visualize or palpate the sciatic nerve and that it “must be palpated to know where it is in order to protect it.” He further stated that there was no mention in the operative report of retractor placement to protect the sciatic nerve. When questioned whether it was possible to pull on the sciatic nerve if the Grievant used retractors only anteriorly or medially to the acetabulum, Dr. Soren responded, “The sciatic nerve falls in the way if it’s not held back. There is nothing there that states that the nerve was protected … If you have the retractor medial of the acetabulum, you are in the area not too far away from the nerve and it could hurt the nerve … Yes (the nerve is posterior), but he is not going to get medial into the acetabulum or anteriorly of the acetabulum. The nerve is right there.”

Dr. Soren also stated in his deposition that the Grievant had improperly placed the acetabular component at an excessive angle and that the component itself was too large for the socket, resulting in an overhang “such that (it) could damage the sciatic nerve by rubbing or friction and cause further problems.” At trial, Dr. Soren testified that anything over a 45-degree angle in placement of the cup is unacceptable and “certainly 60-65 is grossly unacceptable.” When asked whether the amount of overhang could be determined based on images, Dr. Soren testified, “No, you can’t tell on these films because you have metal on top of metal. You have the 2-dimensional film. If you really want to know how it overhangs, you get a CAT scan and you’ll know, but there is definitely an overhang on that.”

Also in his deposition, Dr. Soren stated that the X-ray showed the cup projected beyond the acetabulum and that it was not always possible to determine how much protrusion existed on a 2-dimensional film. He further stated that he could not determine if the protrusion was 1 mm or 4 mm on that particular film because he “didn’t measure exactly.”

Dr. Soren opined that limb lengthening is a possible and known cause of sciatic nerve damage, that angulation increases the likelihood of damage to the sciatic nerve, and that the amount of leg lengthening that occurred as a result of the surgical procedure was more than the acceptable amount. “It was around 1.8 cm” and that could “put a stretch on the sciatic nerve … throw the pelvis into a skewed position when one side is higher than the other.” Dr. Soren declared “they're wrong,” referencing a well-known orthopaedic text that stated that sciatic nerve damage does not occur unless the nerve has been lengthened by more than 4 cm.

When Dr. Soren was questioned regarding the muscle strength rating as documented by the Grievant on the second day postoperatively and whether a 4 out of 5 rating would be compatible with a severe foot drop, he testified, “In the classification of 5 out of 5, 4 out of 5—going down, 3 out of 5, 2 out of 5, 1 out of 5 would be a complete foot drop…” He further stated, in reference to the muscle strength rating noted in an electromyography (EMG) report dated almost 2 years following the initial/right hip replacement, “… but he’s using a different category. His 4 out of 5 can be a complete foot drop … you are comparing apples to oranges. When a neurologist goes to a classification, 5 out of 5 is normal; 4 out of 5 is very, very weak. They don’t go down usually lower than that in this.” He also stated that he hadn’t examined the patient and did not know whether she had sustained a complete foot drop then added, “But I have read all his [the neurologist’s] notes…”

The AAOS Committee on Professionalism (COP) met in executive session, and having reviewed all submissions from both parties, determined that a prima facie case existed and that a hearing was warranted. On March 13, 2010, the COP conducted a hearing at which both parties were present. After thorough consideration, the COP Grievance Hearing Panel found Dr. Soren in violation of Mandatory Standards 3, 4, 7, and 8. He was not found in violation of Standards 1, 5, 12, 13 and 15.

The COP Grievance Hearing Panel determined that Dr. Soren did not evaluate the medical condition and care provided in light of generally accepted standards at the time. Dr. Soren repeatedly maintained the opinion that there had been no change in standards, including those related to documentation as well as orthopaedic surgical practice, since 1989, the time he had discontinued performing surgery. Dr. Soren’s trial testimony indicated that he never objectively measured the cup angles or leg lengths about which he was making his determinations and rendering conclusions. He provided expert witness testimony regarding acceptable cup position, leg length, cup size, and sciatic nerve anatomy that were not substantiated by the literature.

The COP Grievance Hearing Panel found that Dr. Soren did not exhibit knowledge about the standard of care for this case during the relevant time period. His opinion that it is the standard of care to palpate the sciatic nerve and specifically document in the operative note retractor placement and how the nerve was protected during the operation, as well as his characterization of excessive leg lengthening, does not accurately reflect the scientific evidence or accepted practice standards. Dr. Soren stated that a significant portion of his trial testimony regarding the issue of his interpretation of the neurologist’s opinions regarding dorsiflexor weakness was incorrectly transcribed; however, the trial transcript does not appear to reflect these types of errors.

Dr. Soren’s trial testimony revealed that, after extensive questioning, he admitted he could not be certain he had ever performed an uncemented total hip arthroplasty (THA). At the grievance hearing, Dr. Soren continued to be vague regarding his experience with THA. The COP Grievance Hearing Panel found that his testimony and response to questions at the hearing, as well as his deposition and trial testimonies, indicated that he lacked the current and relevant knowledge required of an expert witness for this specific case.

Dr. Soren appealed the findings and recommendation of the COP Grievance Hearing Panel and, on November 5, 2010, the Judiciary Committee conducted an Appeal Hearing at which both parties were present. Regarding Dr. Soren’s comments on the sciatic nerve, the Judiciary Committee found that he did not distinguish between his personal opinion and standard of care. Dr. Soren also admitted that his testimony regarding his interpretation of the neurologist’s manual muscle testing scores was “wrong” and he no longer asserted that it could only be a transcription error.

After careful deliberation, the Judiciary Committee unanimously agreed that the AAOS had afforded both parties due process. The Judiciary Committee further agreed that Dr. Soren had violated Mandatory Standards 3, 4, 7 and 8 and upheld the recommendation of the COP Grievance Hearing Panel that Dr. Soren be suspended for 2 years.

On June 11, 2011, the AAOS Board of Directors considered the recommendation of the Judiciary Committee and accompanying materials and voted to suspend Stanley Soren, MD, for a period of 2 years due to violations of Mandatory Standards 3, 4, 7, and 8 of the Standards of Professionalism for Orthopaedic Expert Witness Testimony.

Jeffrey K. Wingate, MD
Georgetown, S.C.
1-Year Suspension

On December 16, 2009, a grievance was submitted against Jeffrey K. Wingate, MD, alleging violations of the Standards of Professionalism (SOPs) for Orthopaedic Expert Witness Testimony, Mandatory Standards 2, 3, 4, and 6. The grievance arose from statements made by Dr. Wingate in an affidavit and in his deposition testimony as a subsequent treating physician in a medical liability lawsuit. The AAOS Committee on Professionalism (COP) met in executive session and, having reviewed all submissions from both sides, determined that a prima facie case existed and that a hearing was warranted.

The patient, a 45-year-old male, had been involved in a motor vehicle accident approximately 8 weeks prior to being seen by the Grievant in September 2004. The patient complained of severe pain in the right buttock, thigh, leg, and low back and workup revealed a lateral herniated disk at L3-L4 effacing the L-3 nerve root. Examination revealed weakness in the right leg in comparison to the left leg and spinal stenosis at L2-L3, L3-L4, and L4-L5. Physical therapy did not result in significant improvement in his symptoms and the patient elected to proceed to surgery.

In February 2005, the patient underwent a decompressive laminectomy of L2, L3, L4, and L-5, as well as excision of a far lateral foraminal disk herniation on the right at L3-L4. In addition, the patient underwent a fusion from L-2 to L-4 with segmental instrumentation and interbody fusion at L2-L3 and L3-L4 with PEEK cages and bone morphogenetic protein.

On postoperative day 1 at approximately 2 a.m. or 3 a.m., the Grievant was notified that the patient complained of loss of sensation in the left lower extremity, as well as an inability to move the left leg. Physical examination reportedly revealed an insensate left leg and trace movement of the hip flexor and quadriceps on the left; the left extensor hallucis longus, tibialis anterior, and plantiflexors scored 3 out of a possible 5 in a manual muscle test. The right lower extremity and rectal exam were reportedly normal.

Options were discussed with the patient and it was elected not to wait the 4 hours to 6 hours it would take to obtain an MRI scan and risk further progressive neurologic deficit. The patient underwent an immediate re-exploration. No significant hematoma was found, and the wound was irrigated and closed over two Hemovac drains.

The patient was seen for his first postoperative visit 2 weeks later. Office records documented that the patient complained his left lower extremity “still did not feel normal” and that there was discomfort in the area of the left greater trochanter and hip. At that time, the patient was able to ambulate with a walker. It was noted that there was active dorsiflexion and plantar flexion of his feet and toes and he could fire his quadriceps, but that strength on the left was somewhat diminished compared to the right side. Hamstring strength was reported as good and it was documented that X-rays revealed intact hardware.

Although the patient’s mobility was improving, neurologic recovery was slow over the ensuing months. Magnetic resonance imaging (MRI) reportedly revealed evidence of postoperative changes, but no herniation or stenosis. The Grievant documented that the cages “looked to be in good position.” Electromyography (EMG) revealed evidence of active L-3, L-4, and L-5 radiculopathy on the left side and very mild L3-L4 radiculopathy on the right side. At the end of July 2005, office notes stated that X-rays revealed “a consolidating fusion consistent with his postoperative status.”

The patient was last seen by the Grievant in October 2005. It was documented that the patient had been having right buttock, as well as trochanteric, pain and was referred for pain management.

The patient was subsequently seen by the Respondent, Dr. Wingate, who ultimately performed revision surgery in February 2009. At the time of surgery, the cage on the left at L2-L3 was noted to be solidly fixed. Dr. Wingate reported that the cage was “more than 1.5 cm posteriorly and positioned into the mid and left side of the thecal sac.” He remarked “significant retraction against the thecal sac was required in order to retrieve it from its mid thecal position.”

On Friday, October 1, 2010, the Committee on Professionalism conducted a hearing based on the grievance brought against Dr. Jeffrey K. Wingate. Both parties were present at the hearing and Dr. Wingate was accompanied by his attorney and a witness on his behalf. The COP Grievance Hearing Panel carefully reviewed all of the materials submitted and, after due deliberation, found Dr. Wingate in violation of Mandatory Standards 2, 3, 4 and 6.

The COP Grievance Hearing Panel found that Dr. Wingate did not provide opinions and/or factual testimony in a fair and impartial manner and, therefore, was in violation of Mandatory Standard 2. At times during his testimony, Dr. Wingate was both dogmatic and absolute in some of his opinions. For example, Dr. Wingate testified, “There absolutely should have been within the standard of care, an imaging study before the patient was returned to the operating room.” Dr. Wingate also opined, “In this case, with two functioning Hemovac drains, there was almost a zero percent chance that a hematoma could have caused a neurologic problem related to the left lower extremity.” When asked if cages could move from appropriate to inappropriate back to appropriate position, Dr. Wingate responded, “They absolutely could have.”

The COP Grievance Hearing Panel also found that Dr. Wingate did not evaluate the medical condition and care provided in light of generally accepted standards at the time, place, and in the context of care delivered. Dr. Wingate testified that there should have been an imaging study obtained before the patient went back to the operating room and when questioned during deposition as to the type of study, Dr. Wingate stated, “The board answer in this case is a computed tomography (CT) scan.” During questioning by the COP Grievance Hearing Panel, Dr. Wingate claimed, “The MRI scan or the myelogram/CT, I think ,is the perfect way to evaluate this patient after surgery” and later stated, “A CT scan would have been better than not having anything; I do not think it is the gold standard in this case in this complication.”

At no time did Dr. Wingate opine that an exploration without a prior imaging study was a reasonable alternative considering the situation and circumstances. When Dr. Wingate was asked whether the manipulation of the nerves during the surgery to place the cage could have caused injury to the nerves, Dr. Wingate’s response was “absolutely.” He further stated that he did not agree this was the cause of the type of complaints the patient was experiencing immediately postoperatively because the patient had exactly the same manipulation of his right-sided nerve roots as he had on his left-sided nerve roots.

Dr. Wingate delivered his testimony in absolute terms, leaving little room for differences of opinion, or even the inevitable and genuine variances in scientific evidence used to reach decisions on medical treatment. The COP Grievance Hearing Panel found that this type of expert witness opinion is not indicative of a careful evaluation of the patient’s medical condition and the medical care provided in light of generally accepted standards at the time, place, and in the context of care delivered. As such, Dr. Wingate’s expert opinion violated Mandatory Standard 3.

With regard to Standard 4, the COP Grievance Hearing Panel found that Dr. Wingate condemned performance that fell within the generally accepted practice standards. Concerning the issue of surgical exploration without performing an imaging study, the Grievant evaluated the patient in a timely manner, discussed the options with the patient, outlined his reasoning for not performing the imaging study, and then ultimately explored the patient to assess for a cause of the neurologic deterioration. Dr. Wingate condemned this care, stating that an imaging study should have absolutely been performed prior to bringing the patient back to the operating room.

The COP Grievance Hearing Panel found that Dr. Wingate did not “seek and review all pertinent medical records related to a particular patient prior to rendering an opinion on the medical or surgical management of the patient,” as Mandatory Statement 6 clearly requires. Dr. Wingate testified that he did not see the preoperative or the early postoperative MRI scans and did not see any of the plain films that were obtained by the Grievant. The COP Grievance Hearing Panel found that the review of “a limited number of records and imaging studies” does not satisfy the requirements of Mandatory Standard 6.

Dr. Wingate appealed the findings and recommendation of the COP Grievance Hearing Panel, and the Judiciary Committee conducted an appeal hearing on February 19, 2011. Both parties were present. Dr. Wingate, during the appeal hearing, apologized to the Grievant and to the AAOS, stating that he had made inaccurate, dogmatic, and absolute statements in his deposition, thereby acknowledging that his testimony had not been fair and impartial. The Judiciary Committee unanimously agreed that the AAOS had afforded both parties due process and upheld the findings and recommendations of the COP Grievance Hearing Panel.

On June 11, 2011, the AAOS Board of Directors considered the recommendation of the Judiciary Committee and accompanying materials and voted to suspend Jeffrey K. Wingate, MD, for a period of 1 year due to violations of Mandatory Standards 2, 3, 4, and 6 of the Standards of Professionalism for Orthopaedic Expert Witness Testimony.