Pain tolerance and orthopedic surgery outcomes: what clinicians should know

Pain tolerance and orthopedic surgery outcomes may be related, but clinicians need to distinguish a patient’s reported pain, their response to a standardized stimulus, and their postoperative recovery. These measures capture different aspects of the pain experience.

For orthopedic surgeons and perioperative teams, the practical question is whether a preoperative assessment can help anticipate postoperative pain-management needs. Lanny Johnson, M.D. described a historical assessment involving orthopedic patients that explored individual differences in pain tolerance. Published research using other pain-sensitivity tests has examined a similar question, with mixed findings.

The evidence supports further investigation, not treating any single test as a validated predictor of postoperative pain or medication requirements.

Why individual pain tolerance matters in orthopedic surgery

Patients undergoing similar orthopedic procedures can report different levels of pain and have different experiences during recovery. Understanding those differences could help clinicians discuss expectations and plan postoperative care more individually.

Pain tolerance is one possible factor to examine, but it is not interchangeable with pain intensity or pain sensitivity. A patient’s rating of their usual tolerance describes their own perception. Their response to a controlled stimulus provides a different type of observation. Neither measure, by itself, describes the full postoperative experience.

For clinical teams, the relevant question is whether a preoperative measure adds useful information to the assessment already being performed.

A useful assessment would need to do more than identify differences between patients. It would need to show that those differences relate consistently to outcomes that matter, such as postoperative pain ratings, analgesic use, ability to participate in rehabilitation, or recovery milestones.

That distinction matters when interpreting Dr. Johnson’s presentation. The assessment he described was an exploration of individual pain responses. The information available from the presentation does not establish that the test can predict outcomes after a particular operation.

Self-reported pain tolerance and observed pain responses measure different things

Self-report is a patient’s account of their own experience. A standardized stimulus, by contrast, gives the clinician an opportunity to observe a response under a defined testing condition.

These approaches may provide different information, so they should not automatically be treated as interchangeable.

The distinction is important when interpreting an apparent mismatch between a patient’s self-rating and observed response. Such a mismatch does not automatically mean that the patient has misjudged their pain tolerance. It may indicate that the measures capture different dimensions of pain.

For example, a patient might describe their tolerance as high but respond strongly to one particular stimulus. That finding would raise a question about how well the self-rating corresponds to the test, not provide a definitive forecast of how the patient will feel after surgery.

Clinicians should avoid using a single test result to dismiss a patient’s account of pain. Any assessment intended for clinical use needs to be interpreted alongside the patient’s history, current symptoms, procedure, and postoperative course.

What Lanny Johnson, M.D. described about the ball-drop assessment

In his presentation, Lanny Johnson, M.D. described an assessment involving 1,000 consecutive orthopedic patients seen in private practice between November 5, 1993, and February 28, 1995.

According to Dr. Johnson’s account, patients rated their own pain tolerance on a scale of 1 to 10. The assessment then used a ball-drop stimulus involving the fingernail or index finger and the knee, with patients keeping their eyes closed. The stated intent was to reduce the influence of the examiner on the patient’s response.

Dr. Johnson reported two notable observations:

• 28% of patients who rated their pain tolerance above 5 out of 10 experienced more pain or discomfort during testing than their peers.
• 3% of patients showed greater tolerance than expected.

These figures come from Dr. Johnson’s presentation. The presentation does not provide enough bibliographic information to independently verify the original publication, study methods, statistical analysis, or definitions used to classify a response as greater or less than expected.

The reported findings suggest that self-rated tolerance and observed response did not always align in this group. They do not establish why the measures differed, whether the differences were clinically meaningful, or whether the test predicted postoperative pain.

The ball-drop assessment should also not be conflated with pressure algometry, a different method used in some published research to measure pain sensitivity. Findings from one testing method cannot automatically validate another.

What published research says about preoperative pain sensitivity

Published studies have investigated whether preoperative pain sensitivity is associated with pain and recovery after total joint arthroplasty. These studies offer relevant context, but they do not validate the ball-drop assessment described by Dr. Johnson.

A 2020 prospective study of 178 patients undergoing total knee arthroplasty examined preoperative pain sensitivity using an algometer. The study reported associations between lower preoperative pressure-pain thresholds and outcomes including postoperative pain, analgesic requirements, and mobility milestones.

Reference: Palanisami DR, et al. “Assessing Preoperative Pain Sensitivity Predicts the Postoperative Analgesic Requirement and Recovery after Total Knee Arthroplasty: A Prospective Study of 178 Patients.” The Journal of Arthroplasty. 2020;35(12):3545-3553. PubMed record.

A separate 2016 study examined pressure-pain thresholds as a potential predictor of acute postoperative pain following total joint arthroplasty. In its sample of 41 patients, the researchers did not find significant correlations between the preoperative thresholds and the outcomes examined.

Reference: Haghverdian BA, Wright DJ, Schwarzkopf R. “Pressure Pain Threshold as a Predictor of Acute Postoperative Pain Following Total Joint Arthroplasty.” PubMed record.

Taken together, these studies do not support a simple conclusion that a preoperative pain-sensitivity test reliably predicts postoperative outcomes. One reported associations, while another did not find significant correlations in its sample. Differences in study design, sample size, testing methods, and outcome definitions matter when interpreting those results.

Most importantly, these studies used pressure-pain threshold testing, not the ball-drop procedure described in Dr. Johnson’s presentation. They provide context for the broader research question, but they do not independently verify his reported figures or establish the predictive validity of his assessment.

How pain tolerance testing could inform postoperative planning

A preoperative pain-tolerance measure would be clinically useful only if it adds information beyond the usual assessment and helps teams make better decisions.

Potential applications to investigate include:

• Preoperative discussions: Exploring whether a patient’s self-rating and response to a standardized stimulus provide complementary information when discussing pain expectations.
• Individualized monitoring: Testing whether preoperative measures identify groups who may benefit from closer assessment of pain and recovery after surgery.
• Analgesic planning: Evaluating whether a measure is associated with subsequent analgesic use, while avoiding the assumption that a test result determines an individual’s medication needs.
• Rehabilitation outcomes: Examining whether preoperative pain sensitivity relates to participation in rehabilitation or the timing of defined recovery milestones.

These are research questions, not established uses of the ball-drop assessment.

For example, a study could record preoperative pain-tolerance ratings and test responses before a defined orthopedic procedure. Researchers could then compare those measures with prespecified postoperative outcomes, such as pain scores at defined intervals, analgesic consumption, and time to a defined mobility milestone.

The analysis would need to determine whether the test provides predictive information beyond other relevant clinical variables. A relationship between a test result and an outcome would not, by itself, prove that using the test improves care.

Likewise, a measure associated with higher analgesic use should not be interpreted as a direct prescription guide. Medication decisions require clinical judgment and an assessment of the patient’s circumstances. A test would need to be validated for its intended purpose before it could reasonably inform a clinical pathway.

What would be needed before clinical adoption

Before a pain-tolerance test could be incorporated into routine orthopedic practice, its reliability, validity, and clinical usefulness would need to be established.

Reliability asks whether the test produces consistent results under comparable conditions. Researchers would need a clearly defined protocol for administering the stimulus, recording the response, and interpreting the score.

Validity asks whether the test measures what it is intended to measure. A test designed to assess response to a brief stimulus may not capture the same experience as pain after an operation. Its relationship to postoperative outcomes needs to be tested directly.

Predictive performance asks how well the measure forecasts specified outcomes in the population where it would be used. This requires a defined outcome, an appropriate study design, and analysis of whether the test adds information beyond other available predictors.

Clinical utility asks whether using the result leads to better decisions or outcomes. Even a test associated with postoperative pain may not improve care if it does not change management in a useful way.

A stronger evidence base would include prospective studies with clearly described patient populations, standardized testing procedures, prespecified outcomes, and transparent statistical methods. Independent validation would be needed before applying findings broadly across different orthopedic procedures or patient groups.

The historical account in Dr. Johnson’s presentation raises a question worth studying: how closely does a patient’s self-assessment correspond to their response to a standardized pain stimulus? It does not, on its own, answer the separate question of whether the test can forecast postoperative outcomes.

Practical next steps for orthopedic researchers and clinicians

Teams interested in this question can take several steps without treating an unvalidated test as a clinical decision tool.

1. Define the intended use. Specify whether the goal is to understand pain sensitivity, anticipate postoperative pain scores, estimate analgesic use, or examine rehabilitation outcomes.
2. Standardize the measurement. Document the stimulus, testing conditions, scoring method, and rules for interpreting responses.
3. Select clinically meaningful outcomes. Define when and how pain, medication use, and recovery milestones will be measured.
4. Compare against existing assessment. Determine whether the test adds predictive information beyond routine clinical data and patient-reported measures.
5. Validate findings independently. Test performance in an appropriate new sample before recommending broad use.
6. Assess clinical impact. If predictive performance is demonstrated, investigate whether using the result changes management and improves patient outcomes.

For now, preoperative pain-tolerance assessment is best treated as a research question rather than a proven method for selecting postoperative analgesia. Dr. Johnson’s presentation provides a historical account of observed differences between self-rated tolerance and responses to a stimulus. Separate published studies show that the relationship between preoperative pain sensitivity and postoperative outcomes warrants further study, but the findings are not uniform.

The next step is rigorous validation that connects a defined test to outcomes clinicians and patients care about.

Frequently asked questions

Can a patient’s pain tolerance be measured before orthopedic surgery?

A patient’s self-reported tolerance can be recorded, and researchers can assess responses to standardized stimuli. However, the method and purpose need to be defined clearly. A preoperative measure should not be assumed to predict postoperative pain without direct validation.

Does high pain tolerance mean a patient will need less pain medication after surgery?

Not necessarily. A pain-tolerance rating alone does not establish how much medication a patient will need. That relationship must be studied using defined outcomes and an appropriate patient population.

What was the ball-drop test described by Lanny Johnson, M.D.?

Dr. Johnson described a test in which orthopedic patients rated their pain tolerance and then responded to a ball-drop stimulus involving the fingernail or index finger and the knee, with their eyes closed. His presentation reported differences between self-rated tolerance and observed responses. The available source does not establish that this test is validated for predicting postoperative outcomes.

What does a pressure-pain threshold test measure?

Pressure-pain threshold testing assesses the point at which applied pressure is reported as painful. It is a different method from the ball-drop assessment described by Dr. Johnson, so findings from pressure-algometry studies should not be treated as direct validation of that assessment.

Can preoperative pain sensitivity predict recovery after knee replacement?

Some research has reported associations between preoperative pressure-pain sensitivity and postoperative pain, analgesic requirements, or mobility milestones. Other research has not found significant correlations. The available findings do not establish that one test reliably predicts recovery for every patient.

Why might a patient’s self-rated pain tolerance differ from their test response?

The two measures may capture different aspects of the pain experience. A rating reflects the patient’s own assessment, while a standardized stimulus measures a response under specific conditions. A mismatch does not, by itself, establish that either measure is inaccurate.

Should orthopedic surgeons use the ball-drop test to plan postoperative medication?

The available information does not establish that the ball-drop assessment can predict medication needs or improve outcomes. It should not be used as a stand-alone basis for medication decisions without appropriate validation and evidence of clinical utility.

What evidence would support routine use of a preoperative pain-tolerance test?

Evidence would need to establish consistent measurement, validity for the intended purpose, predictive performance in the relevant patient population, and clinical utility. Prospective research and independent validation would help determine whether the test adds useful information to routine assessment.

Does a test that predicts postoperative pain automatically improve patient outcomes?

No. Predictive accuracy and clinical benefit are different questions. Research must establish not only whether a test forecasts an outcome, but also whether using its result leads to better clinical decisions or recovery.

What to do next

• Treat the ball-drop findings as a historical account reported by Dr. Johnson, pending verification of the original publication.
• Keep self-reported pain tolerance, stimulus response, postoperative pain, and analgesic use conceptually separate.
• Review pressure-algometry research as related evidence, not as validation of the ball-drop method.
• Define the specific postoperative outcome a proposed test is intended to predict.
• Require prospective validation before incorporating the test into routine clinical pathways.